Annotate methods that always return this with @CanIgnoreReturnValue

It's always safe to ignore the result of these methods, because the
caller already has a reference to the returned value.

PiperOrigin-RevId: 462388947

extensions/cronet/build.gradle

@@ -24,6 +24,7 @@ dependencies {
     implementation project(modulePrefix + 'library-common')
     implementation project(modulePrefix + 'library-datasource')
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     androidTestImplementation 'androidx.test:rules:' + androidxTestRulesVersion

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetDataSource.java

@@ -41,6 +41,7 @@ import com.google.common.base.Ascii;
 import com.google.common.base.Predicate;
 import com.google.common.net.HttpHeaders;
 import com.google.common.primitives.Longs;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.net.SocketTimeoutException;
@@ -140,6 +141,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
       readTimeoutMs = DEFAULT_READ_TIMEOUT_MILLIS;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public final Factory setDefaultRequestProperties(Map<String, String> defaultRequestProperties) {
       this.defaultRequestProperties.clearAndSet(defaultRequestProperties);
@@ -159,6 +161,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      *     agent of the underlying {@link CronetEngine}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUserAgent(@Nullable String userAgent) {
       this.userAgent = userAgent;
       if (internalFallbackFactory != null) {
@@ -177,6 +180,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      *     UrlRequest.Builder#REQUEST_PRIORITY_*} constants.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setRequestPriority(int requestPriority) {
       this.requestPriority = requestPriority;
       return this;
@@ -190,6 +194,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * @param connectTimeoutMs The connect timeout, in milliseconds, that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setConnectionTimeoutMs(int connectTimeoutMs) {
       this.connectTimeoutMs = connectTimeoutMs;
       if (internalFallbackFactory != null) {
@@ -206,6 +211,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * @param resetTimeoutOnRedirects Whether the connect timeout is reset when a redirect occurs.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setResetTimeoutOnRedirects(boolean resetTimeoutOnRedirects) {
       this.resetTimeoutOnRedirects = resetTimeoutOnRedirects;
       return this;
@@ -221,6 +227,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      *     to the redirect url in the "Cookie" header.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setHandleSetCookieRequests(boolean handleSetCookieRequests) {
       this.handleSetCookieRequests = handleSetCookieRequests;
       return this;
@@ -234,6 +241,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * @param readTimeoutMs The connect timeout, in milliseconds, that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setReadTimeoutMs(int readTimeoutMs) {
       this.readTimeoutMs = readTimeoutMs;
       if (internalFallbackFactory != null) {
@@ -252,6 +260,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      *     predicate that was previously set.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setContentTypePredicate(@Nullable Predicate<String> contentTypePredicate) {
       this.contentTypePredicate = contentTypePredicate;
       if (internalFallbackFactory != null) {
@@ -264,6 +273,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * Sets whether we should keep the POST method and body when we have HTTP 302 redirects for a
      * POST request.
      */
+    @CanIgnoreReturnValue
     public Factory setKeepPostFor302Redirects(boolean keepPostFor302Redirects) {
       this.keepPostFor302Redirects = keepPostFor302Redirects;
       if (internalFallbackFactory != null) {
@@ -282,6 +292,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * @param transferListener The listener that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setTransferListener(@Nullable TransferListener transferListener) {
       this.transferListener = transferListener;
       if (internalFallbackFactory != null) {
@@ -301,6 +312,7 @@ public class CronetDataSource extends BaseDataSource implements HttpDataSource {
      * @deprecated Do not use {@link CronetDataSource} or its factory in cases where a suitable
      *     {@link CronetEngine} is not available. Use the fallback factory directly in such cases.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Factory setFallbackFactory(@Nullable HttpDataSource.Factory fallbackFactory) {
       this.fallbackFactory = fallbackFactory;

extensions/ima/build.gradle

@@ -28,6 +28,7 @@ dependencies {
     api 'com.google.ads.interactivemedia.v3:interactivemedia:3.26.0'
     implementation project(modulePrefix + 'library-core')
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     androidTestImplementation project(modulePrefix + 'testutils')

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaAdsLoader.java

@@ -55,6 +55,7 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -151,6 +152,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @param imaSdkSettings The {@link ImaSdkSettings}.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setImaSdkSettings(ImaSdkSettings imaSdkSettings) {
       this.imaSdkSettings = checkNotNull(imaSdkSettings);
       return this;
@@ -164,6 +166,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @param adErrorListener The ad error listener.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setAdErrorListener(AdErrorListener adErrorListener) {
       this.adErrorListener = checkNotNull(adErrorListener);
       return this;
@@ -176,6 +179,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @param adEventListener The ad event listener.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setAdEventListener(AdEventListener adEventListener) {
       this.adEventListener = checkNotNull(adEventListener);
       return this;
@@ -191,6 +195,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see com.google.ads.interactivemedia.v3.api.player.VideoAdPlayer.VideoAdPlayerCallback
      */
+    @CanIgnoreReturnValue
     public Builder setVideoAdPlayerCallback(
         VideoAdPlayer.VideoAdPlayerCallback videoAdPlayerCallback) {
       this.videoAdPlayerCallback = checkNotNull(videoAdPlayerCallback);
@@ -204,6 +209,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRenderingSettings#setUiElements(Set)
      */
+    @CanIgnoreReturnValue
     public Builder setAdUiElements(Set<UiElement> adUiElements) {
       this.adUiElements = ImmutableSet.copyOf(checkNotNull(adUiElements));
       return this;
@@ -216,6 +222,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdDisplayContainer#setCompanionSlots(Collection)
      */
+    @CanIgnoreReturnValue
     public Builder setCompanionAdSlots(Collection<CompanionAdSlot> companionAdSlots) {
       this.companionAdSlots = ImmutableList.copyOf(checkNotNull(companionAdSlots));
       return this;
@@ -233,6 +240,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRenderingSettings#setMimeTypes(List)
      */
+    @CanIgnoreReturnValue
     public Builder setAdMediaMimeTypes(List<String> adMediaMimeTypes) {
       this.adMediaMimeTypes = ImmutableList.copyOf(checkNotNull(adMediaMimeTypes));
       return this;
@@ -247,6 +255,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRequest#setContinuousPlayback(boolean)
      */
+    @CanIgnoreReturnValue
     public Builder setEnableContinuousPlayback(boolean enableContinuousPlayback) {
       this.enableContinuousPlayback = enableContinuousPlayback;
       return this;
@@ -265,6 +274,7 @@ public final class ImaAdsLoader implements AdsLoader {
      *     C#TIME_UNSET} for no timeout.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setAdPreloadTimeoutMs(long adPreloadTimeoutMs) {
       checkArgument(adPreloadTimeoutMs == C.TIME_UNSET || adPreloadTimeoutMs > 0);
       this.adPreloadTimeoutMs = adPreloadTimeoutMs;
@@ -278,6 +288,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRequest#setVastLoadTimeout(float)
      */
+    @CanIgnoreReturnValue
     public Builder setVastLoadTimeoutMs(@IntRange(from = 1) int vastLoadTimeoutMs) {
       checkArgument(vastLoadTimeoutMs > 0);
       this.vastLoadTimeoutMs = vastLoadTimeoutMs;
@@ -291,6 +302,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRenderingSettings#setLoadVideoTimeout(int)
      */
+    @CanIgnoreReturnValue
     public Builder setMediaLoadTimeoutMs(@IntRange(from = 1) int mediaLoadTimeoutMs) {
       checkArgument(mediaLoadTimeoutMs > 0);
       this.mediaLoadTimeoutMs = mediaLoadTimeoutMs;
@@ -304,6 +316,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRenderingSettings#setBitrateKbps(int)
      */
+    @CanIgnoreReturnValue
     public Builder setMaxMediaBitrate(@IntRange(from = 1) int bitrate) {
       checkArgument(bitrate > 0);
       this.mediaBitrate = bitrate;
@@ -319,6 +332,7 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see AdsRenderingSettings#setFocusSkipButtonWhenAvailable(boolean)
      */
+    @CanIgnoreReturnValue
     public Builder setFocusSkipButtonWhenAvailable(boolean focusSkipButtonWhenAvailable) {
       this.focusSkipButtonWhenAvailable = focusSkipButtonWhenAvailable;
       return this;
@@ -334,6 +348,7 @@ public final class ImaAdsLoader implements AdsLoader {
      *     beginning playback.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setPlayAdBeforeStartPosition(boolean playAdBeforeStartPosition) {
       this.playAdBeforeStartPosition = playAdBeforeStartPosition;
       return this;
@@ -349,11 +364,13 @@ public final class ImaAdsLoader implements AdsLoader {
      * @return This builder, for convenience.
      * @see ImaSdkSettings#setDebugMode(boolean)
      */
+    @CanIgnoreReturnValue
     public Builder setDebugModeEnabled(boolean debugModeEnabled) {
       this.debugModeEnabled = debugModeEnabled;
       return this;
     }
 
+    @CanIgnoreReturnValue
     @VisibleForTesting
     /* package */ Builder setImaFactory(ImaUtil.ImaFactory imaFactory) {
       this.imaFactory = checkNotNull(imaFactory);

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionMediaSource.java

@@ -92,6 +92,7 @@ import com.google.android.exoplayer2.util.ConditionVariable;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
@@ -132,6 +133,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
       this.contentMediaSourceFactory = contentMediaSourceFactory;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public MediaSource.Factory setLoadErrorHandlingPolicy(
         LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
@@ -139,6 +141,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public MediaSource.Factory setDrmSessionManagerProvider(
         DrmSessionManagerProvider drmSessionManagerProvider) {
@@ -213,6 +216,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
        * @param imaSdkSettings The {@link ImaSdkSettings}.
        * @return This builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public AdsLoader.Builder setImaSdkSettings(ImaSdkSettings imaSdkSettings) {
         this.imaSdkSettings = imaSdkSettings;
         return this;
@@ -225,6 +229,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
        * @param adEventListener The ad event listener.
        * @return This builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public AdsLoader.Builder setAdEventListener(AdEventListener adEventListener) {
         this.adEventListener = adEventListener;
         return this;
@@ -237,6 +242,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
        * @param adErrorListener The {@link AdErrorEvent.AdErrorListener}.
        * @return This builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public AdsLoader.Builder setAdErrorListener(AdErrorEvent.AdErrorListener adErrorListener) {
         this.adErrorListener = adErrorListener;
         return this;
@@ -249,6 +255,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
        * @return This builder, for convenience.
        * @see AdDisplayContainer#setCompanionSlots(Collection)
        */
+      @CanIgnoreReturnValue
       public AdsLoader.Builder setCompanionAdSlots(Collection<CompanionAdSlot> companionAdSlots) {
         this.companionAdSlots = ImmutableList.copyOf(companionAdSlots);
         return this;
@@ -262,6 +269,7 @@ public final class ImaServerSideAdInsertionMediaSource extends CompositeMediaSou
        * @param state The state to resume with.
        * @return This builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public AdsLoader.Builder setAdsLoaderState(State state) {
         this.state = state;
         return this;

extensions/ima/src/main/java/com/google/android/exoplayer2/ext/ima/ImaServerSideAdInsertionUriBuilder.java

@@ -28,6 +28,7 @@ import com.google.ads.interactivemedia.v3.api.StreamRequest.StreamFormat;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.C.ContentType;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -83,6 +84,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param adsId The ads identifier.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setAdsId(String adsId) {
     this.adsId = adsId;
     return this;
@@ -94,6 +96,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param assetKey Live stream asset key.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setAssetKey(@Nullable String assetKey) {
     this.assetKey = assetKey;
     return this;
@@ -107,6 +110,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param authToken Live stream authorization token.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setAuthToken(@Nullable String authToken) {
     this.authToken = authToken;
     return this;
@@ -118,6 +122,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param contentSourceId VOD stream content source id.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setContentSourceId(@Nullable String contentSourceId) {
     this.contentSourceId = contentSourceId;
     return this;
@@ -129,6 +134,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param videoId VOD stream video id.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setVideoId(@Nullable String videoId) {
     this.videoId = videoId;
     return this;
@@ -140,6 +146,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param format {@link C#TYPE_DASH} or {@link C#TYPE_HLS}.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setFormat(@ContentType int format) {
     checkArgument(format == C.CONTENT_TYPE_DASH || format == C.CONTENT_TYPE_HLS);
     this.format = format;
@@ -154,6 +161,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param apiKey Stream api key.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setApiKey(@Nullable String apiKey) {
     this.apiKey = apiKey;
     return this;
@@ -167,6 +175,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param streamActivityMonitorId ID for debugging the stream with the stream activity monitor.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setStreamActivityMonitorId(
       @Nullable String streamActivityMonitorId) {
     this.streamActivityMonitorId = streamActivityMonitorId;
@@ -185,6 +194,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param adTagParameters A map of extra parameters to pass to the ad server.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setAdTagParameters(
       Map<String, String> adTagParameters) {
     this.adTagParameters = ImmutableMap.copyOf(adTagParameters);
@@ -198,6 +208,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param manifestSuffix Stream manifest's suffix.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setManifestSuffix(@Nullable String manifestSuffix) {
     this.manifestSuffix = manifestSuffix;
     return this;
@@ -211,6 +222,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param contentUrl Deep link to the content's screen.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setContentUrl(@Nullable String contentUrl) {
     this.contentUrl = contentUrl;
     return this;
@@ -224,6 +236,7 @@ public final class ImaServerSideAdInsertionUriBuilder {
    * @param loadVideoTimeoutMs The timeout after which to give up resolving the video URI.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ImaServerSideAdInsertionUriBuilder setLoadVideoTimeoutMs(int loadVideoTimeoutMs) {
     this.loadVideoTimeoutMs = loadVideoTimeoutMs;
     return this;

extensions/media2/build.gradle

@@ -18,6 +18,7 @@ dependencies {
     implementation 'androidx.collection:collection:' + androidxCollectionVersion
     implementation 'androidx.concurrent:concurrent-futures:' + androidxFuturesVersion
     api 'androidx.media2:media2-session:' + androidxMedia2Version
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

extensions/media2/src/main/java/com/google/android/exoplayer2/ext/media2/SessionCallbackBuilder.java

@@ -36,6 +36,7 @@ import androidx.media2.session.SessionCommand;
 import androidx.media2.session.SessionCommandGroup;
 import androidx.media2.session.SessionResult;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -394,6 +395,7 @@ public final class SessionCallbackBuilder {
    * @see MediaSession.SessionCallback#onSetRating(MediaSession, ControllerInfo, String, Rating)
    * @see androidx.media2.session.MediaController#setRating(String, Rating)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setRatingCallback(@Nullable RatingCallback ratingCallback) {
     this.ratingCallback = ratingCallback;
     return this;
@@ -408,6 +410,7 @@ public final class SessionCallbackBuilder {
    *     Bundle)
    * @see androidx.media2.session.MediaController#sendCustomCommand(SessionCommand, Bundle)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setCustomCommandProvider(
       @Nullable CustomCommandProvider customCommandProvider) {
     this.customCommandProvider = customCommandProvider;
@@ -425,6 +428,7 @@ public final class SessionCallbackBuilder {
    * @see androidx.media2.session.MediaController#setMediaItem(String)
    * @see androidx.media2.session.MediaController#setPlaylist(List, MediaMetadata)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setMediaItemProvider(
       @Nullable MediaItemProvider mediaItemProvider) {
     this.mediaItemProvider = mediaItemProvider;
@@ -437,6 +441,7 @@ public final class SessionCallbackBuilder {
    * @param allowedCommandProvider A allowed command provider.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setAllowedCommandProvider(
       @Nullable AllowedCommandProvider allowedCommandProvider) {
     this.allowedCommandProvider = allowedCommandProvider;
@@ -453,6 +458,7 @@ public final class SessionCallbackBuilder {
    * @see MediaController#skipBackward()
    * @see MediaController#skipForward()
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setSkipCallback(@Nullable SkipCallback skipCallback) {
     this.skipCallback = skipCallback;
     return this;
@@ -465,6 +471,7 @@ public final class SessionCallbackBuilder {
    * @return This builder.
    * @see MediaSession.SessionCallback#onPostConnect(MediaSession, ControllerInfo)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setPostConnectCallback(
       @Nullable PostConnectCallback postConnectCallback) {
     this.postConnectCallback = postConnectCallback;
@@ -478,6 +485,7 @@ public final class SessionCallbackBuilder {
    * @return This builder.
    * @see MediaSession.SessionCallback#onDisconnected(MediaSession, ControllerInfo)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setDisconnectedCallback(
       @Nullable DisconnectedCallback disconnectedCallback) {
     this.disconnectedCallback = disconnectedCallback;
@@ -493,6 +501,7 @@ public final class SessionCallbackBuilder {
    * @see MediaSession.SessionCallback#onRewind(MediaSession, MediaSession.ControllerInfo)
    * @see #setSeekTimeoutMs(int)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setRewindIncrementMs(int rewindMs) {
     this.rewindMs = rewindMs;
     return this;
@@ -507,6 +516,7 @@ public final class SessionCallbackBuilder {
    * @see MediaSession.SessionCallback#onFastForward(MediaSession, MediaSession.ControllerInfo)
    * @see #setSeekTimeoutMs(int)
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setFastForwardIncrementMs(int fastForwardMs) {
     this.fastForwardMs = fastForwardMs;
     return this;
@@ -521,6 +531,7 @@ public final class SessionCallbackBuilder {
    *     forever.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public SessionCallbackBuilder setSeekTimeoutMs(int seekTimeoutMs) {
     this.seekTimeoutMs = seekTimeoutMs;
     return this;

extensions/okhttp/build.gradle

@@ -19,6 +19,7 @@ dependencies {
     implementation project(modulePrefix + 'library-common')
     implementation project(modulePrefix + 'library-datasource')
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     testImplementation project(modulePrefix + 'testutils')

extensions/okhttp/src/main/java/com/google/android/exoplayer2/ext/okhttp/OkHttpDataSource.java

@@ -39,6 +39,7 @@ import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Predicate;
 import com.google.common.net.HttpHeaders;
 import com.google.common.util.concurrent.SettableFuture;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InterruptedIOException;
@@ -93,6 +94,7 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
       defaultRequestProperties = new RequestProperties();
     }
 
+    @CanIgnoreReturnValue
     @Override
     public final Factory setDefaultRequestProperties(Map<String, String> defaultRequestProperties) {
       this.defaultRequestProperties.clearAndSet(defaultRequestProperties);
@@ -109,6 +111,7 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
      *     agent of the underlying {@link OkHttpClient}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUserAgent(@Nullable String userAgent) {
       this.userAgent = userAgent;
       return this;
@@ -122,6 +125,7 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
      * @param cacheControl The cache control that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCacheControl(@Nullable CacheControl cacheControl) {
       this.cacheControl = cacheControl;
       return this;
@@ -138,6 +142,7 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
      *     predicate that was previously set.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setContentTypePredicate(@Nullable Predicate<String> contentTypePredicate) {
       this.contentTypePredicate = contentTypePredicate;
       return this;
@@ -153,6 +158,7 @@ public class OkHttpDataSource extends BaseDataSource implements HttpDataSource {
      * @param transferListener The listener that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setTransferListener(@Nullable TransferListener transferListener) {
       this.transferListener = transferListener;
       return this;

extensions/rtmp/build.gradle

@@ -18,6 +18,7 @@ dependencies {
     implementation project(modulePrefix + 'library-datasource')
     implementation 'io.antmedia:rtmp-client:3.2.0'
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion
     testImplementation project(modulePrefix + 'library-core')
     testImplementation project(modulePrefix + 'testutils')

extensions/rtmp/src/main/java/com/google/android/exoplayer2/ext/rtmp/RtmpDataSource.java

@@ -25,6 +25,7 @@ import com.google.android.exoplayer2.upstream.BaseDataSource;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.upstream.TransferListener;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import io.antmedia.rtmp_client.RtmpClient;
 import io.antmedia.rtmp_client.RtmpClient.RtmpIOException;
 import java.io.IOException;
@@ -51,6 +52,7 @@ public final class RtmpDataSource extends BaseDataSource {
      * @param transferListener The listener that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setTransferListener(@Nullable TransferListener transferListener) {
       this.transferListener = transferListener;
       return this;

library/common/src/main/java/com/google/android/exoplayer2/Format.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.ColorInfo;
 import com.google.common.base.Joiner;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -250,6 +251,7 @@ public final class Format implements Bundleable {
      * @param id The {@link Format#id}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setId(@Nullable String id) {
       this.id = id;
       return this;
@@ -262,6 +264,7 @@ public final class Format implements Bundleable {
      * @param id The {@link Format#id}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setId(int id) {
       this.id = Integer.toString(id);
       return this;
@@ -273,6 +276,7 @@ public final class Format implements Bundleable {
      * @param label The {@link Format#label}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLabel(@Nullable String label) {
       this.label = label;
       return this;
@@ -284,6 +288,7 @@ public final class Format implements Bundleable {
      * @param language The {@link Format#language}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLanguage(@Nullable String language) {
       this.language = language;
       return this;
@@ -295,6 +300,7 @@ public final class Format implements Bundleable {
      * @param selectionFlags The {@link Format#selectionFlags}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSelectionFlags(@C.SelectionFlags int selectionFlags) {
       this.selectionFlags = selectionFlags;
       return this;
@@ -306,6 +312,7 @@ public final class Format implements Bundleable {
      * @param roleFlags The {@link Format#roleFlags}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRoleFlags(@C.RoleFlags int roleFlags) {
       this.roleFlags = roleFlags;
       return this;
@@ -317,6 +324,7 @@ public final class Format implements Bundleable {
      * @param averageBitrate The {@link Format#averageBitrate}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setAverageBitrate(int averageBitrate) {
       this.averageBitrate = averageBitrate;
       return this;
@@ -328,6 +336,7 @@ public final class Format implements Bundleable {
      * @param peakBitrate The {@link Format#peakBitrate}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPeakBitrate(int peakBitrate) {
       this.peakBitrate = peakBitrate;
       return this;
@@ -339,6 +348,7 @@ public final class Format implements Bundleable {
      * @param codecs The {@link Format#codecs}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setCodecs(@Nullable String codecs) {
       this.codecs = codecs;
       return this;
@@ -350,6 +360,7 @@ public final class Format implements Bundleable {
      * @param metadata The {@link Format#metadata}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMetadata(@Nullable Metadata metadata) {
       this.metadata = metadata;
       return this;
@@ -363,6 +374,7 @@ public final class Format implements Bundleable {
      * @param containerMimeType The {@link Format#containerMimeType}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setContainerMimeType(@Nullable String containerMimeType) {
       this.containerMimeType = containerMimeType;
       return this;
@@ -376,6 +388,7 @@ public final class Format implements Bundleable {
      * @param sampleMimeType {@link Format#sampleMimeType}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSampleMimeType(@Nullable String sampleMimeType) {
       this.sampleMimeType = sampleMimeType;
       return this;
@@ -387,6 +400,7 @@ public final class Format implements Bundleable {
      * @param maxInputSize The {@link Format#maxInputSize}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxInputSize(int maxInputSize) {
       this.maxInputSize = maxInputSize;
       return this;
@@ -398,6 +412,7 @@ public final class Format implements Bundleable {
      * @param initializationData The {@link Format#initializationData}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setInitializationData(@Nullable List<byte[]> initializationData) {
       this.initializationData = initializationData;
       return this;
@@ -409,6 +424,7 @@ public final class Format implements Bundleable {
      * @param drmInitData The {@link Format#drmInitData}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setDrmInitData(@Nullable DrmInitData drmInitData) {
       this.drmInitData = drmInitData;
       return this;
@@ -420,6 +436,7 @@ public final class Format implements Bundleable {
      * @param subsampleOffsetUs The {@link Format#subsampleOffsetUs}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSubsampleOffsetUs(long subsampleOffsetUs) {
       this.subsampleOffsetUs = subsampleOffsetUs;
       return this;
@@ -433,6 +450,7 @@ public final class Format implements Bundleable {
      * @param width The {@link Format#width}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setWidth(int width) {
       this.width = width;
       return this;
@@ -444,6 +462,7 @@ public final class Format implements Bundleable {
      * @param height The {@link Format#height}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setHeight(int height) {
       this.height = height;
       return this;
@@ -455,6 +474,7 @@ public final class Format implements Bundleable {
      * @param frameRate The {@link Format#frameRate}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setFrameRate(float frameRate) {
       this.frameRate = frameRate;
       return this;
@@ -466,6 +486,7 @@ public final class Format implements Bundleable {
      * @param rotationDegrees The {@link Format#rotationDegrees}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRotationDegrees(int rotationDegrees) {
       this.rotationDegrees = rotationDegrees;
       return this;
@@ -477,6 +498,7 @@ public final class Format implements Bundleable {
      * @param pixelWidthHeightRatio The {@link Format#pixelWidthHeightRatio}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPixelWidthHeightRatio(float pixelWidthHeightRatio) {
       this.pixelWidthHeightRatio = pixelWidthHeightRatio;
       return this;
@@ -488,6 +510,7 @@ public final class Format implements Bundleable {
      * @param projectionData The {@link Format#projectionData}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setProjectionData(@Nullable byte[] projectionData) {
       this.projectionData = projectionData;
       return this;
@@ -499,6 +522,7 @@ public final class Format implements Bundleable {
      * @param stereoMode The {@link Format#stereoMode}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setStereoMode(@C.StereoMode int stereoMode) {
       this.stereoMode = stereoMode;
       return this;
@@ -510,6 +534,7 @@ public final class Format implements Bundleable {
      * @param colorInfo The {@link Format#colorInfo}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setColorInfo(@Nullable ColorInfo colorInfo) {
       this.colorInfo = colorInfo;
       return this;
@@ -523,6 +548,7 @@ public final class Format implements Bundleable {
      * @param channelCount The {@link Format#channelCount}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setChannelCount(int channelCount) {
       this.channelCount = channelCount;
       return this;
@@ -534,6 +560,7 @@ public final class Format implements Bundleable {
      * @param sampleRate The {@link Format#sampleRate}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSampleRate(int sampleRate) {
       this.sampleRate = sampleRate;
       return this;
@@ -545,6 +572,7 @@ public final class Format implements Bundleable {
      * @param pcmEncoding The {@link Format#pcmEncoding}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPcmEncoding(@C.PcmEncoding int pcmEncoding) {
       this.pcmEncoding = pcmEncoding;
       return this;
@@ -556,6 +584,7 @@ public final class Format implements Bundleable {
      * @param encoderDelay The {@link Format#encoderDelay}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEncoderDelay(int encoderDelay) {
       this.encoderDelay = encoderDelay;
       return this;
@@ -567,6 +596,7 @@ public final class Format implements Bundleable {
      * @param encoderPadding The {@link Format#encoderPadding}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEncoderPadding(int encoderPadding) {
       this.encoderPadding = encoderPadding;
       return this;
@@ -580,6 +610,7 @@ public final class Format implements Bundleable {
      * @param accessibilityChannel The {@link Format#accessibilityChannel}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setAccessibilityChannel(int accessibilityChannel) {
       this.accessibilityChannel = accessibilityChannel;
       return this;
@@ -593,6 +624,7 @@ public final class Format implements Bundleable {
      * @param cryptoType The {@link C.CryptoType}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setCryptoType(@C.CryptoType int cryptoType) {
       this.cryptoType = cryptoType;
       return this;

library/common/src/main/java/com/google/android/exoplayer2/MediaItem.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.InlineMe;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
@@ -126,6 +127,7 @@ public final class MediaItem implements Bundleable {
      *
      * <p>By default {@link #DEFAULT_MEDIA_ID} is used.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaId(String mediaId) {
       this.mediaId = checkNotNull(mediaId);
       return this;
@@ -138,6 +140,7 @@ public final class MediaItem implements Bundleable {
      * during {@link #build()} and no other {@code Builder} methods that would populate {@link
      * MediaItem#localConfiguration} should be called.
      */
+    @CanIgnoreReturnValue
     public Builder setUri(@Nullable String uri) {
       return setUri(uri == null ? null : Uri.parse(uri));
     }
@@ -149,6 +152,7 @@ public final class MediaItem implements Bundleable {
      * during {@link #build()} and no other {@code Builder} methods that would populate {@link
      * MediaItem#localConfiguration} should be called.
      */
+    @CanIgnoreReturnValue
     public Builder setUri(@Nullable Uri uri) {
       this.uri = uri;
       return this;
@@ -163,12 +167,14 @@ public final class MediaItem implements Bundleable {
      *
      * @param mimeType The MIME type.
      */
+    @CanIgnoreReturnValue
     public Builder setMimeType(@Nullable String mimeType) {
       this.mimeType = mimeType;
       return this;
     }
 
     /** Sets the {@link ClippingConfiguration}, defaults to {@link ClippingConfiguration#UNSET}. */
+    @CanIgnoreReturnValue
     public Builder setClippingConfiguration(ClippingConfiguration clippingConfiguration) {
       this.clippingConfiguration = clippingConfiguration.buildUpon();
       return this;
@@ -178,6 +184,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setClippingConfiguration(ClippingConfiguration)} and {@link
      *     ClippingConfiguration.Builder#setStartPositionMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setClipStartPositionMs(@IntRange(from = 0) long startPositionMs) {
       clippingConfiguration.setStartPositionMs(startPositionMs);
@@ -188,6 +195,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setClippingConfiguration(ClippingConfiguration)} and {@link
      *     ClippingConfiguration.Builder#setEndPositionMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setClipEndPositionMs(long endPositionMs) {
       clippingConfiguration.setEndPositionMs(endPositionMs);
@@ -198,6 +206,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setClippingConfiguration(ClippingConfiguration)} and {@link
      *     ClippingConfiguration.Builder#setRelativeToLiveWindow(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setClipRelativeToLiveWindow(boolean relativeToLiveWindow) {
       clippingConfiguration.setRelativeToLiveWindow(relativeToLiveWindow);
@@ -208,6 +217,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setClippingConfiguration(ClippingConfiguration)} and {@link
      *     ClippingConfiguration.Builder#setRelativeToDefaultPosition(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setClipRelativeToDefaultPosition(boolean relativeToDefaultPosition) {
       clippingConfiguration.setRelativeToDefaultPosition(relativeToDefaultPosition);
@@ -218,6 +228,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setClippingConfiguration(ClippingConfiguration)} and {@link
      *     ClippingConfiguration.Builder#setStartsAtKeyFrame(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setClipStartsAtKeyFrame(boolean startsAtKeyFrame) {
       clippingConfiguration.setStartsAtKeyFrame(startsAtKeyFrame);
@@ -225,6 +236,7 @@ public final class MediaItem implements Bundleable {
     }
 
     /** Sets the optional DRM configuration. */
+    @CanIgnoreReturnValue
     public Builder setDrmConfiguration(@Nullable DrmConfiguration drmConfiguration) {
       this.drmConfiguration =
           drmConfiguration != null ? drmConfiguration.buildUpon() : new DrmConfiguration.Builder();
@@ -235,6 +247,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setLicenseUri(Uri)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmLicenseUri(@Nullable Uri licenseUri) {
       drmConfiguration.setLicenseUri(licenseUri);
@@ -245,6 +258,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setLicenseUri(String)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmLicenseUri(@Nullable String licenseUri) {
       drmConfiguration.setLicenseUri(licenseUri);
@@ -257,6 +271,7 @@ public final class MediaItem implements Bundleable {
      *     DrmConfiguration.Builder#setLicenseRequestHeaders(Map)} doesn't accept null, use an empty
      *     map to clear the headers.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmLicenseRequestHeaders(
         @Nullable Map<String, String> licenseRequestHeaders) {
@@ -269,6 +284,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and pass the {@code uuid} to
      *     {@link DrmConfiguration.Builder#Builder(UUID)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmUuid(@Nullable UUID uuid) {
       drmConfiguration.setNullableScheme(uuid);
@@ -279,6 +295,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setMultiSession(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmMultiSession(boolean multiSession) {
       drmConfiguration.setMultiSession(multiSession);
@@ -289,6 +306,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setForceDefaultLicenseUri(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmForceDefaultLicenseUri(boolean forceDefaultLicenseUri) {
       drmConfiguration.setForceDefaultLicenseUri(forceDefaultLicenseUri);
@@ -299,6 +317,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setPlayClearContentWithoutKey(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmPlayClearContentWithoutKey(boolean playClearContentWithoutKey) {
       drmConfiguration.setPlayClearContentWithoutKey(playClearContentWithoutKey);
@@ -309,6 +328,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setForceSessionsForAudioAndVideoTracks(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmSessionForClearPeriods(boolean sessionForClearPeriods) {
       drmConfiguration.setForceSessionsForAudioAndVideoTracks(sessionForClearPeriods);
@@ -321,6 +341,7 @@ public final class MediaItem implements Bundleable {
      *     DrmConfiguration.Builder#setForcedSessionTrackTypes(List)} doesn't accept null, use an
      *     empty list to clear the contents.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmSessionForClearTypes(
         @Nullable List<@C.TrackType Integer> sessionForClearTypes) {
@@ -333,6 +354,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setDrmConfiguration(DrmConfiguration)} and {@link
      *     DrmConfiguration.Builder#setKeySetId(byte[])} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDrmKeySetId(@Nullable byte[] keySetId) {
       drmConfiguration.setKeySetId(keySetId);
@@ -348,6 +370,7 @@ public final class MediaItem implements Bundleable {
      * <p>If {@link #setUri} is passed a non-null {@code uri}, the stream keys are used to create a
      * {@link LocalConfiguration} object. Otherwise they will be ignored.
      */
+    @CanIgnoreReturnValue
     public Builder setStreamKeys(@Nullable List<StreamKey> streamKeys) {
       this.streamKeys =
           streamKeys != null && !streamKeys.isEmpty()
@@ -361,6 +384,7 @@ public final class MediaItem implements Bundleable {
      *
      * <p>This method should only be called if {@link #setUri} is passed a non-null value.
      */
+    @CanIgnoreReturnValue
     public Builder setCustomCacheKey(@Nullable String customCacheKey) {
       this.customCacheKey = customCacheKey;
       return this;
@@ -371,6 +395,7 @@ public final class MediaItem implements Bundleable {
      *     #setSubtitleConfigurations(List)} doesn't accept null, use an empty list to clear the
      *     contents.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setSubtitles(@Nullable List<Subtitle> subtitles) {
       this.subtitleConfigurations =
@@ -383,6 +408,7 @@ public final class MediaItem implements Bundleable {
      *
      * <p>This method should only be called if {@link #setUri} is passed a non-null value.
      */
+    @CanIgnoreReturnValue
     public Builder setSubtitleConfigurations(List<SubtitleConfiguration> subtitleConfigurations) {
       this.subtitleConfigurations = ImmutableList.copyOf(subtitleConfigurations);
       return this;
@@ -393,6 +419,7 @@ public final class MediaItem implements Bundleable {
      *
      * <p>This method should only be called if {@link #setUri} is passed a non-null value.
      */
+    @CanIgnoreReturnValue
     public Builder setAdsConfiguration(@Nullable AdsConfiguration adsConfiguration) {
       this.adsConfiguration = adsConfiguration;
       return this;
@@ -403,6 +430,7 @@ public final class MediaItem implements Bundleable {
      *     with {@link Uri#parse(String)} and pass the result to {@link
      *     AdsConfiguration.Builder#Builder(Uri)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setAdTagUri(@Nullable String adTagUri) {
       return setAdTagUri(adTagUri != null ? Uri.parse(adTagUri) : null);
@@ -412,6 +440,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setAdsConfiguration(AdsConfiguration)} and pass the {@code adTagUri}
      *     to {@link AdsConfiguration.Builder#Builder(Uri)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setAdTagUri(@Nullable Uri adTagUri) {
       return setAdTagUri(adTagUri, /* adsId= */ null);
@@ -422,6 +451,7 @@ public final class MediaItem implements Bundleable {
      *     {@link AdsConfiguration.Builder#Builder(Uri)} and the {@code adsId} to {@link
      *     AdsConfiguration.Builder#setAdsId(Object)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setAdTagUri(@Nullable Uri adTagUri, @Nullable Object adsId) {
       this.adsConfiguration =
@@ -430,6 +460,7 @@ public final class MediaItem implements Bundleable {
     }
 
     /** Sets the {@link LiveConfiguration}. Defaults to {@link LiveConfiguration#UNSET}. */
+    @CanIgnoreReturnValue
     public Builder setLiveConfiguration(LiveConfiguration liveConfiguration) {
       this.liveConfiguration = liveConfiguration.buildUpon();
       return this;
@@ -439,6 +470,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setLiveConfiguration(LiveConfiguration)} and {@link
      *     LiveConfiguration.Builder#setTargetOffsetMs(long)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLiveTargetOffsetMs(long liveTargetOffsetMs) {
       liveConfiguration.setTargetOffsetMs(liveTargetOffsetMs);
@@ -449,6 +481,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setLiveConfiguration(LiveConfiguration)} and {@link
      *     LiveConfiguration.Builder#setMinOffsetMs(long)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLiveMinOffsetMs(long liveMinOffsetMs) {
       liveConfiguration.setMinOffsetMs(liveMinOffsetMs);
@@ -459,6 +492,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setLiveConfiguration(LiveConfiguration)} and {@link
      *     LiveConfiguration.Builder#setMaxOffsetMs(long)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLiveMaxOffsetMs(long liveMaxOffsetMs) {
       liveConfiguration.setMaxOffsetMs(liveMaxOffsetMs);
@@ -469,6 +503,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setLiveConfiguration(LiveConfiguration)} and {@link
      *     LiveConfiguration.Builder#setMinPlaybackSpeed(float)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLiveMinPlaybackSpeed(float minPlaybackSpeed) {
       liveConfiguration.setMinPlaybackSpeed(minPlaybackSpeed);
@@ -479,6 +514,7 @@ public final class MediaItem implements Bundleable {
      * @deprecated Use {@link #setLiveConfiguration(LiveConfiguration)} and {@link
      *     LiveConfiguration.Builder#setMaxPlaybackSpeed(float)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLiveMaxPlaybackSpeed(float maxPlaybackSpeed) {
       liveConfiguration.setMaxPlaybackSpeed(maxPlaybackSpeed);
@@ -492,18 +528,21 @@ public final class MediaItem implements Bundleable {
      *
      * <p>This method should only be called if {@link #setUri} is passed a non-null value.
      */
+    @CanIgnoreReturnValue
     public Builder setTag(@Nullable Object tag) {
       this.tag = tag;
       return this;
     }
 
     /** Sets the media metadata. */
+    @CanIgnoreReturnValue
     public Builder setMediaMetadata(MediaMetadata mediaMetadata) {
       this.mediaMetadata = mediaMetadata;
       return this;
     }
 
     /** Sets the request metadata. */
+    @CanIgnoreReturnValue
     public Builder setRequestMetadata(RequestMetadata requestMetadata) {
       this.requestMetadata = requestMetadata;
       return this;
@@ -587,6 +626,7 @@ public final class MediaItem implements Bundleable {
       }
 
       /** Sets the {@link UUID} of the protection scheme. */
+      @CanIgnoreReturnValue
       public Builder setScheme(UUID scheme) {
         this.scheme = scheme;
         return this;
@@ -596,6 +636,7 @@ public final class MediaItem implements Bundleable {
        * @deprecated This only exists to support the deprecated {@link
        *     MediaItem.Builder#setDrmUuid(UUID)}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       private Builder setNullableScheme(@Nullable UUID scheme) {
         this.scheme = scheme;
@@ -603,24 +644,28 @@ public final class MediaItem implements Bundleable {
       }
 
       /** Sets the optional default DRM license server URI. */
+      @CanIgnoreReturnValue
       public Builder setLicenseUri(@Nullable Uri licenseUri) {
         this.licenseUri = licenseUri;
         return this;
       }
 
       /** Sets the optional default DRM license server URI. */
+      @CanIgnoreReturnValue
       public Builder setLicenseUri(@Nullable String licenseUri) {
         this.licenseUri = licenseUri == null ? null : Uri.parse(licenseUri);
         return this;
       }
 
       /** Sets the optional request headers attached to DRM license requests. */
+      @CanIgnoreReturnValue
       public Builder setLicenseRequestHeaders(Map<String, String> licenseRequestHeaders) {
         this.licenseRequestHeaders = ImmutableMap.copyOf(licenseRequestHeaders);
         return this;
       }
 
       /** Sets whether multi session is enabled. */
+      @CanIgnoreReturnValue
       public Builder setMultiSession(boolean multiSession) {
         this.multiSession = multiSession;
         return this;
@@ -630,6 +675,7 @@ public final class MediaItem implements Bundleable {
        * Sets whether to always use the default DRM license server URI even if the media specifies
        * its own DRM license server URI.
        */
+      @CanIgnoreReturnValue
       public Builder setForceDefaultLicenseUri(boolean forceDefaultLicenseUri) {
         this.forceDefaultLicenseUri = forceDefaultLicenseUri;
         return this;
@@ -639,6 +685,7 @@ public final class MediaItem implements Bundleable {
        * Sets whether clear samples within protected content should be played when keys for the
        * encrypted part of the content have yet to be loaded.
        */
+      @CanIgnoreReturnValue
       public Builder setPlayClearContentWithoutKey(boolean playClearContentWithoutKey) {
         this.playClearContentWithoutKey = playClearContentWithoutKey;
         return this;
@@ -647,6 +694,7 @@ public final class MediaItem implements Bundleable {
       /**
        * @deprecated Use {@link #setForceSessionsForAudioAndVideoTracks(boolean)} instead.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       @InlineMe(
           replacement =
@@ -663,6 +711,7 @@ public final class MediaItem implements Bundleable {
        * <p>This method overrides what has been set by previously calling {@link
        * #setForcedSessionTrackTypes(List)}.
        */
+      @CanIgnoreReturnValue
       public Builder setForceSessionsForAudioAndVideoTracks(
           boolean forceSessionsForAudioAndVideoTracks) {
         this.setForcedSessionTrackTypes(
@@ -682,6 +731,7 @@ public final class MediaItem implements Bundleable {
        * <p>This method overrides what has been set by previously calling {@link
        * #setForceSessionsForAudioAndVideoTracks(boolean)}.
        */
+      @CanIgnoreReturnValue
       public Builder setForcedSessionTrackTypes(
           List<@C.TrackType Integer> forcedSessionTrackTypes) {
         this.forcedSessionTrackTypes = ImmutableList.copyOf(forcedSessionTrackTypes);
@@ -695,6 +745,7 @@ public final class MediaItem implements Bundleable {
        * release an existing offline license (see {@code DefaultDrmSessionManager#setMode(int
        * mode,byte[] offlineLicenseKeySetId)}).
        */
+      @CanIgnoreReturnValue
       public Builder setKeySetId(@Nullable byte[] keySetId) {
         this.keySetId = keySetId != null ? Arrays.copyOf(keySetId, keySetId.length) : null;
         return this;
@@ -837,6 +888,7 @@ public final class MediaItem implements Bundleable {
       }
 
       /** Sets the ad tag URI to load. */
+      @CanIgnoreReturnValue
       public Builder setAdTagUri(Uri adTagUri) {
         this.adTagUri = adTagUri;
         return this;
@@ -848,6 +900,7 @@ public final class MediaItem implements Bundleable {
        * <p>See details on {@link AdsConfiguration#adsId} for how the ads identifier is used and how
        * it's calculated if not explicitly set.
        */
+      @CanIgnoreReturnValue
       public Builder setAdsId(@Nullable Object adsId) {
         this.adsId = adsId;
         return this;
@@ -1065,6 +1118,7 @@ public final class MediaItem implements Bundleable {
        *
        * <p>Defaults to {@link C#TIME_UNSET}, indicating the media-defined default will be used.
        */
+      @CanIgnoreReturnValue
       public Builder setTargetOffsetMs(long targetOffsetMs) {
         this.targetOffsetMs = targetOffsetMs;
         return this;
@@ -1077,6 +1131,7 @@ public final class MediaItem implements Bundleable {
        *
        * <p>Defaults to {@link C#TIME_UNSET}, indicating the media-defined default will be used.
        */
+      @CanIgnoreReturnValue
       public Builder setMinOffsetMs(long minOffsetMs) {
         this.minOffsetMs = minOffsetMs;
         return this;
@@ -1089,6 +1144,7 @@ public final class MediaItem implements Bundleable {
        *
        * <p>Defaults to {@link C#TIME_UNSET}, indicating the media-defined default will be used.
        */
+      @CanIgnoreReturnValue
       public Builder setMaxOffsetMs(long maxOffsetMs) {
         this.maxOffsetMs = maxOffsetMs;
         return this;
@@ -1099,6 +1155,7 @@ public final class MediaItem implements Bundleable {
        *
        * <p>Defaults to {@link C#RATE_UNSET}, indicating the media-defined default will be used.
        */
+      @CanIgnoreReturnValue
       public Builder setMinPlaybackSpeed(float minPlaybackSpeed) {
         this.minPlaybackSpeed = minPlaybackSpeed;
         return this;
@@ -1109,6 +1166,7 @@ public final class MediaItem implements Bundleable {
        *
        * <p>Defaults to {@link C#RATE_UNSET}, indicating the media-defined default will be used.
        */
+      @CanIgnoreReturnValue
       public Builder setMaxPlaybackSpeed(float maxPlaybackSpeed) {
         this.maxPlaybackSpeed = maxPlaybackSpeed;
         return this;
@@ -1298,42 +1356,49 @@ public final class MediaItem implements Bundleable {
       }
 
       /** Sets the {@link Uri} to the subtitle file. */
+      @CanIgnoreReturnValue
       public Builder setUri(Uri uri) {
         this.uri = uri;
         return this;
       }
 
       /** Sets the MIME type. */
+      @CanIgnoreReturnValue
       public Builder setMimeType(@Nullable String mimeType) {
         this.mimeType = mimeType;
         return this;
       }
 
       /** Sets the optional language of the subtitle file. */
+      @CanIgnoreReturnValue
       public Builder setLanguage(@Nullable String language) {
         this.language = language;
         return this;
       }
 
       /** Sets the flags used for track selection. */
+      @CanIgnoreReturnValue
       public Builder setSelectionFlags(@C.SelectionFlags int selectionFlags) {
         this.selectionFlags = selectionFlags;
         return this;
       }
 
       /** Sets the role flags. These are used for track selection. */
+      @CanIgnoreReturnValue
       public Builder setRoleFlags(@C.RoleFlags int roleFlags) {
         this.roleFlags = roleFlags;
         return this;
       }
 
       /** Sets the optional label for this subtitle track. */
+      @CanIgnoreReturnValue
       public Builder setLabel(@Nullable String label) {
         this.label = label;
         return this;
       }
 
       /** Sets the optional ID for this subtitle track. */
+      @CanIgnoreReturnValue
       public Builder setId(@Nullable String id) {
         this.id = id;
         return this;
@@ -1506,6 +1571,7 @@ public final class MediaItem implements Bundleable {
        * Sets the optional start position in milliseconds which must be a value larger than or equal
        * to zero (Default: 0).
        */
+      @CanIgnoreReturnValue
       public Builder setStartPositionMs(@IntRange(from = 0) long startPositionMs) {
         Assertions.checkArgument(startPositionMs >= 0);
         this.startPositionMs = startPositionMs;
@@ -1517,6 +1583,7 @@ public final class MediaItem implements Bundleable {
        * to zero, or {@link C#TIME_END_OF_SOURCE} to end when playback reaches the end of media
        * (Default: {@link C#TIME_END_OF_SOURCE}).
        */
+      @CanIgnoreReturnValue
       public Builder setEndPositionMs(long endPositionMs) {
         Assertions.checkArgument(endPositionMs == C.TIME_END_OF_SOURCE || endPositionMs >= 0);
         this.endPositionMs = endPositionMs;
@@ -1528,6 +1595,7 @@ public final class MediaItem implements Bundleable {
        * {@code false}, live streams end when playback reaches the end position in live window seen
        * when the media is first loaded (Default: {@code false}).
        */
+      @CanIgnoreReturnValue
       public Builder setRelativeToLiveWindow(boolean relativeToLiveWindow) {
         this.relativeToLiveWindow = relativeToLiveWindow;
         return this;
@@ -1537,6 +1605,7 @@ public final class MediaItem implements Bundleable {
        * Sets whether the start position and the end position are relative to the default position
        * in the window (Default: {@code false}).
        */
+      @CanIgnoreReturnValue
       public Builder setRelativeToDefaultPosition(boolean relativeToDefaultPosition) {
         this.relativeToDefaultPosition = relativeToDefaultPosition;
         return this;
@@ -1546,6 +1615,7 @@ public final class MediaItem implements Bundleable {
        * Sets whether the start point is guaranteed to be a key frame. If {@code false}, the
        * playback transition into the clip may not be seamless (Default: {@code false}).
        */
+      @CanIgnoreReturnValue
       public Builder setStartsAtKeyFrame(boolean startsAtKeyFrame) {
         this.startsAtKeyFrame = startsAtKeyFrame;
         return this;
@@ -1731,18 +1801,21 @@ public final class MediaItem implements Bundleable {
       }
 
       /** Sets the URI of the requested media, or null if not known or applicable. */
+      @CanIgnoreReturnValue
       public Builder setMediaUri(@Nullable Uri mediaUri) {
         this.mediaUri = mediaUri;
         return this;
       }
 
       /** Sets the search query for the requested media, or null if not applicable. */
+      @CanIgnoreReturnValue
       public Builder setSearchQuery(@Nullable String searchQuery) {
         this.searchQuery = searchQuery;
         return this;
       }
 
       /** Sets optional extras {@link Bundle}. */
+      @CanIgnoreReturnValue
       public Builder setExtras(@Nullable Bundle extras) {
         this.extras = extras;
         return this;

library/common/src/main/java/com/google/android/exoplayer2/MediaMetadata.java

@@ -29,6 +29,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.metadata.Metadata;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Objects;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -114,30 +115,35 @@ public final class MediaMetadata implements Bundleable {
     }
 
     /** Sets the title. */
+    @CanIgnoreReturnValue
     public Builder setTitle(@Nullable CharSequence title) {
       this.title = title;
       return this;
     }
 
     /** Sets the artist. */
+    @CanIgnoreReturnValue
     public Builder setArtist(@Nullable CharSequence artist) {
       this.artist = artist;
       return this;
     }
 
     /** Sets the album title. */
+    @CanIgnoreReturnValue
     public Builder setAlbumTitle(@Nullable CharSequence albumTitle) {
       this.albumTitle = albumTitle;
       return this;
     }
 
     /** Sets the album artist. */
+    @CanIgnoreReturnValue
     public Builder setAlbumArtist(@Nullable CharSequence albumArtist) {
       this.albumArtist = albumArtist;
       return this;
     }
 
     /** Sets the display title. */
+    @CanIgnoreReturnValue
     public Builder setDisplayTitle(@Nullable CharSequence displayTitle) {
       this.displayTitle = displayTitle;
       return this;
@@ -148,24 +154,28 @@ public final class MediaMetadata implements Bundleable {
      *
      * <p>This is the secondary title of the media, unrelated to closed captions.
      */
+    @CanIgnoreReturnValue
     public Builder setSubtitle(@Nullable CharSequence subtitle) {
       this.subtitle = subtitle;
       return this;
     }
 
     /** Sets the description. */
+    @CanIgnoreReturnValue
     public Builder setDescription(@Nullable CharSequence description) {
       this.description = description;
       return this;
     }
 
     /** Sets the user {@link Rating}. */
+    @CanIgnoreReturnValue
     public Builder setUserRating(@Nullable Rating userRating) {
       this.userRating = userRating;
       return this;
     }
 
     /** Sets the overall {@link Rating}. */
+    @CanIgnoreReturnValue
     public Builder setOverallRating(@Nullable Rating overallRating) {
       this.overallRating = overallRating;
       return this;
@@ -175,6 +185,7 @@ public final class MediaMetadata implements Bundleable {
      * @deprecated Use {@link #setArtworkData(byte[] data, Integer pictureType)} or {@link
      *     #maybeSetArtworkData(byte[] data, int pictureType)}, providing a {@link PictureType}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setArtworkData(@Nullable byte[] artworkData) {
       return setArtworkData(artworkData, /* artworkDataType= */ null);
@@ -184,6 +195,7 @@ public final class MediaMetadata implements Bundleable {
      * Sets the artwork data as a compressed byte array with an associated {@link PictureType
      * artworkDataType}.
      */
+    @CanIgnoreReturnValue
     public Builder setArtworkData(
         @Nullable byte[] artworkData, @Nullable @PictureType Integer artworkDataType) {
       this.artworkData = artworkData == null ? null : artworkData.clone();
@@ -199,6 +211,7 @@ public final class MediaMetadata implements Bundleable {
      * <p>Use {@link #setArtworkData(byte[], Integer)} to set the artwork data without checking the
      * {@link PictureType}.
      */
+    @CanIgnoreReturnValue
     public Builder maybeSetArtworkData(byte[] artworkData, @PictureType int artworkDataType) {
       if (this.artworkData == null
           || Util.areEqual(artworkDataType, PICTURE_TYPE_FRONT_COVER)
@@ -210,30 +223,35 @@ public final class MediaMetadata implements Bundleable {
     }
 
     /** Sets the artwork {@link Uri}. */
+    @CanIgnoreReturnValue
     public Builder setArtworkUri(@Nullable Uri artworkUri) {
       this.artworkUri = artworkUri;
       return this;
     }
 
     /** Sets the track number. */
+    @CanIgnoreReturnValue
     public Builder setTrackNumber(@Nullable Integer trackNumber) {
       this.trackNumber = trackNumber;
       return this;
     }
 
     /** Sets the total number of tracks. */
+    @CanIgnoreReturnValue
     public Builder setTotalTrackCount(@Nullable Integer totalTrackCount) {
       this.totalTrackCount = totalTrackCount;
       return this;
     }
 
     /** Sets the {@link FolderType}. */
+    @CanIgnoreReturnValue
     public Builder setFolderType(@Nullable @FolderType Integer folderType) {
       this.folderType = folderType;
       return this;
     }
 
     /** Sets whether the media is playable. */
+    @CanIgnoreReturnValue
     public Builder setIsPlayable(@Nullable Boolean isPlayable) {
       this.isPlayable = isPlayable;
       return this;
@@ -242,12 +260,14 @@ public final class MediaMetadata implements Bundleable {
     /**
      * @deprecated Use {@link #setRecordingYear(Integer)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setYear(@Nullable Integer year) {
       return setRecordingYear(year);
     }
 
     /** Sets the year of the recording date. */
+    @CanIgnoreReturnValue
     public Builder setRecordingYear(@Nullable Integer recordingYear) {
       this.recordingYear = recordingYear;
       return this;
@@ -258,6 +278,7 @@ public final class MediaMetadata implements Bundleable {
      *
      * <p>Value should be between 1 and 12.
      */
+    @CanIgnoreReturnValue
     public Builder setRecordingMonth(
         @Nullable @IntRange(from = 1, to = 12) Integer recordingMonth) {
       this.recordingMonth = recordingMonth;
@@ -269,12 +290,14 @@ public final class MediaMetadata implements Bundleable {
      *
      * <p>Value should be between 1 and 31.
      */
+    @CanIgnoreReturnValue
     public Builder setRecordingDay(@Nullable @IntRange(from = 1, to = 31) Integer recordingDay) {
       this.recordingDay = recordingDay;
       return this;
     }
 
     /** Sets the year of the release date. */
+    @CanIgnoreReturnValue
     public Builder setReleaseYear(@Nullable Integer releaseYear) {
       this.releaseYear = releaseYear;
       return this;
@@ -285,6 +308,7 @@ public final class MediaMetadata implements Bundleable {
      *
      * <p>Value should be between 1 and 12.
      */
+    @CanIgnoreReturnValue
     public Builder setReleaseMonth(@Nullable @IntRange(from = 1, to = 12) Integer releaseMonth) {
       this.releaseMonth = releaseMonth;
       return this;
@@ -295,60 +319,70 @@ public final class MediaMetadata implements Bundleable {
      *
      * <p>Value should be between 1 and 31.
      */
+    @CanIgnoreReturnValue
     public Builder setReleaseDay(@Nullable @IntRange(from = 1, to = 31) Integer releaseDay) {
       this.releaseDay = releaseDay;
       return this;
     }
 
     /** Sets the writer. */
+    @CanIgnoreReturnValue
     public Builder setWriter(@Nullable CharSequence writer) {
       this.writer = writer;
       return this;
     }
 
     /** Sets the composer. */
+    @CanIgnoreReturnValue
     public Builder setComposer(@Nullable CharSequence composer) {
       this.composer = composer;
       return this;
     }
 
     /** Sets the conductor. */
+    @CanIgnoreReturnValue
     public Builder setConductor(@Nullable CharSequence conductor) {
       this.conductor = conductor;
       return this;
     }
 
     /** Sets the disc number. */
+    @CanIgnoreReturnValue
     public Builder setDiscNumber(@Nullable Integer discNumber) {
       this.discNumber = discNumber;
       return this;
     }
 
     /** Sets the total number of discs. */
+    @CanIgnoreReturnValue
     public Builder setTotalDiscCount(@Nullable Integer totalDiscCount) {
       this.totalDiscCount = totalDiscCount;
       return this;
     }
 
     /** Sets the genre. */
+    @CanIgnoreReturnValue
     public Builder setGenre(@Nullable CharSequence genre) {
       this.genre = genre;
       return this;
     }
 
     /** Sets the compilation. */
+    @CanIgnoreReturnValue
     public Builder setCompilation(@Nullable CharSequence compilation) {
       this.compilation = compilation;
       return this;
     }
 
     /** Sets the name of the station streaming the media. */
+    @CanIgnoreReturnValue
     public Builder setStation(@Nullable CharSequence station) {
       this.station = station;
       return this;
     }
 
     /** Sets the extras {@link Bundle}. */
+    @CanIgnoreReturnValue
     public Builder setExtras(@Nullable Bundle extras) {
       this.extras = extras;
       return this;
@@ -363,6 +397,7 @@ public final class MediaMetadata implements Bundleable {
      * <p>In the event that multiple {@link Metadata.Entry} objects within the {@link Metadata}
      * relate to the same {@link MediaMetadata} field, then the last one will be used.
      */
+    @CanIgnoreReturnValue
     public Builder populateFromMetadata(Metadata metadata) {
       for (int i = 0; i < metadata.length(); i++) {
         Metadata.Entry entry = metadata.get(i);
@@ -381,6 +416,7 @@ public final class MediaMetadata implements Bundleable {
      * <p>In the event that multiple {@link Metadata.Entry} objects within any of the {@link
      * Metadata} relate to the same {@link MediaMetadata} field, then the last one will be used.
      */
+    @CanIgnoreReturnValue
     public Builder populateFromMetadata(List<Metadata> metadataList) {
       for (int i = 0; i < metadataList.size(); i++) {
         Metadata metadata = metadataList.get(i);
@@ -393,6 +429,7 @@ public final class MediaMetadata implements Bundleable {
     }
 
     /** Populates all the fields from {@code mediaMetadata}, provided they are non-null. */
+    @CanIgnoreReturnValue
     public Builder populate(@Nullable MediaMetadata mediaMetadata) {
       if (mediaMetadata == null) {
         return this;

library/common/src/main/java/com/google/android/exoplayer2/Player.java

@@ -40,6 +40,7 @@ import com.google.android.exoplayer2.util.FlagSet;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.VideoSize;
 import com.google.common.base.Objects;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -405,6 +406,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder add(@Command int command) {
         flagsBuilder.add(command);
         return this;
@@ -418,6 +420,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder addIf(@Command int command, boolean condition) {
         flagsBuilder.addIf(command, condition);
         return this;
@@ -430,6 +433,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder addAll(@Command int... commands) {
         flagsBuilder.addAll(commands);
         return this;
@@ -442,6 +446,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder addAll(Commands commands) {
         flagsBuilder.addAll(commands.flags);
         return this;
@@ -453,6 +458,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder addAllCommands() {
         flagsBuilder.addAll(SUPPORTED_COMMANDS);
         return this;
@@ -465,6 +471,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder remove(@Command int command) {
         flagsBuilder.remove(command);
         return this;
@@ -478,6 +485,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder removeIf(@Command int command, boolean condition) {
         flagsBuilder.removeIf(command, condition);
         return this;
@@ -490,6 +498,7 @@ public interface Player {
        * @return This builder.
        * @throws IllegalStateException If {@link #build()} has already been called.
        */
+      @CanIgnoreReturnValue
       public Builder removeAll(@Command int... commands) {
         flagsBuilder.removeAll(commands);
         return this;

library/common/src/main/java/com/google/android/exoplayer2/Timeline.java

@@ -34,6 +34,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.BundleUtil;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.InlineMe;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
@@ -261,6 +262,7 @@ public abstract class Timeline implements Bundleable {
     }
 
     /** Sets the data held by this window. */
+    @CanIgnoreReturnValue
     @SuppressWarnings("deprecation")
     public Window set(
         Object uid,
@@ -624,6 +626,7 @@ public abstract class Timeline implements Bundleable {
      *     period is not within the window.
      * @return This period, for convenience.
      */
+    @CanIgnoreReturnValue
     public Period set(
         @Nullable Object id,
         @Nullable Object uid,
@@ -659,6 +662,7 @@ public abstract class Timeline implements Bundleable {
      *     information has yet to be loaded.
      * @return This period, for convenience.
      */
+    @CanIgnoreReturnValue
     public Period set(
         @Nullable Object id,
         @Nullable Object uid,

library/common/src/main/java/com/google/android/exoplayer2/audio/AudioAttributes.java

@@ -25,6 +25,7 @@ import androidx.annotation.RequiresApi;
 import com.google.android.exoplayer2.Bundleable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -95,30 +96,35 @@ public final class AudioAttributes implements Bundleable {
     }
 
     /** See {@link android.media.AudioAttributes.Builder#setContentType(int)} */
+    @CanIgnoreReturnValue
     public Builder setContentType(@C.AudioContentType int contentType) {
       this.contentType = contentType;
       return this;
     }
 
     /** See {@link android.media.AudioAttributes.Builder#setFlags(int)} */
+    @CanIgnoreReturnValue
     public Builder setFlags(@C.AudioFlags int flags) {
       this.flags = flags;
       return this;
     }
 
     /** See {@link android.media.AudioAttributes.Builder#setUsage(int)} */
+    @CanIgnoreReturnValue
     public Builder setUsage(@C.AudioUsage int usage) {
       this.usage = usage;
       return this;
     }
 
     /** See {@link android.media.AudioAttributes.Builder#setAllowedCapturePolicy(int)}. */
+    @CanIgnoreReturnValue
     public Builder setAllowedCapturePolicy(@C.AudioAllowedCapturePolicy int allowedCapturePolicy) {
       this.allowedCapturePolicy = allowedCapturePolicy;
       return this;
     }
 
     /** See {@link android.media.AudioAttributes.Builder#setSpatializationBehavior(int)}. */
+    @CanIgnoreReturnValue
     public Builder setSpatializationBehavior(@C.SpatializationBehavior int spatializationBehavior) {
       this.spatializationBehavior = spatializationBehavior;
       return this;

library/common/src/main/java/com/google/android/exoplayer2/text/Cue.java

@@ -35,6 +35,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Bundleable;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.common.base.Objects;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -621,6 +622,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#text
      */
+    @CanIgnoreReturnValue
     public Builder setText(CharSequence text) {
       this.text = text;
       return this;
@@ -642,6 +644,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#bitmap
      */
+    @CanIgnoreReturnValue
     public Builder setBitmap(Bitmap bitmap) {
       this.bitmap = bitmap;
       return this;
@@ -665,6 +668,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#textAlignment
      */
+    @CanIgnoreReturnValue
     public Builder setTextAlignment(@Nullable Layout.Alignment textAlignment) {
       this.textAlignment = textAlignment;
       return this;
@@ -688,6 +692,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#multiRowAlignment
      */
+    @CanIgnoreReturnValue
     public Builder setMultiRowAlignment(@Nullable Layout.Alignment multiRowAlignment) {
       this.multiRowAlignment = multiRowAlignment;
       return this;
@@ -700,6 +705,7 @@ public final class Cue implements Bundleable {
      * @see Cue#line
      * @see Cue#lineType
      */
+    @CanIgnoreReturnValue
     public Builder setLine(float line, @LineType int lineType) {
       this.line = line;
       this.lineType = lineType;
@@ -732,6 +738,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#lineAnchor
      */
+    @CanIgnoreReturnValue
     public Builder setLineAnchor(@AnchorType int lineAnchor) {
       this.lineAnchor = lineAnchor;
       return this;
@@ -753,6 +760,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#position
      */
+    @CanIgnoreReturnValue
     public Builder setPosition(float position) {
       this.position = position;
       return this;
@@ -774,6 +782,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#positionAnchor
      */
+    @CanIgnoreReturnValue
     public Builder setPositionAnchor(@AnchorType int positionAnchor) {
       this.positionAnchor = positionAnchor;
       return this;
@@ -795,6 +804,7 @@ public final class Cue implements Bundleable {
      * @see Cue#textSize
      * @see Cue#textSizeType
      */
+    @CanIgnoreReturnValue
     public Builder setTextSize(float textSize, @TextSizeType int textSizeType) {
       this.textSize = textSize;
       this.textSizeType = textSizeType;
@@ -827,6 +837,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#size
      */
+    @CanIgnoreReturnValue
     public Builder setSize(float size) {
       this.size = size;
       return this;
@@ -848,6 +859,7 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#bitmapHeight
      */
+    @CanIgnoreReturnValue
     public Builder setBitmapHeight(float bitmapHeight) {
       this.bitmapHeight = bitmapHeight;
       return this;
@@ -871,6 +883,7 @@ public final class Cue implements Bundleable {
      * @see Cue#windowColor
      * @see Cue#windowColorSet
      */
+    @CanIgnoreReturnValue
     public Builder setWindowColor(@ColorInt int windowColor) {
       this.windowColor = windowColor;
       this.windowColorSet = true;
@@ -878,6 +891,7 @@ public final class Cue implements Bundleable {
     }
 
     /** Sets {@link Cue#windowColorSet} to false. */
+    @CanIgnoreReturnValue
     public Builder clearWindowColor() {
       this.windowColorSet = false;
       return this;
@@ -908,12 +922,14 @@ public final class Cue implements Bundleable {
      *
      * @see Cue#verticalType
      */
+    @CanIgnoreReturnValue
     public Builder setVerticalType(@VerticalType int verticalType) {
       this.verticalType = verticalType;
       return this;
     }
 
     /** Sets the shear angle for this Cue. */
+    @CanIgnoreReturnValue
     public Builder setShearDegrees(float shearDegrees) {
       this.shearDegrees = shearDegrees;
       return this;

library/common/src/main/java/com/google/android/exoplayer2/trackselection/TrackSelectionParameters.java

@@ -36,6 +36,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.primitives.Ints;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -306,6 +307,7 @@ public class TrackSelectionParameters implements Bundleable {
     }
 
     /** Overrides the value of the builder with the value of {@link TrackSelectionParameters}. */
+    @CanIgnoreReturnValue
     protected Builder set(TrackSelectionParameters parameters) {
       init(parameters);
       return this;
@@ -318,6 +320,7 @@ public class TrackSelectionParameters implements Bundleable {
      *
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxVideoSizeSd() {
       return setMaxVideoSize(1279, 719);
     }
@@ -327,6 +330,7 @@ public class TrackSelectionParameters implements Bundleable {
      *
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder clearVideoSizeConstraints() {
       return setMaxVideoSize(Integer.MAX_VALUE, Integer.MAX_VALUE);
     }
@@ -338,6 +342,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param maxVideoHeight Maximum allowed video height in pixels.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxVideoSize(int maxVideoWidth, int maxVideoHeight) {
       this.maxVideoWidth = maxVideoWidth;
       this.maxVideoHeight = maxVideoHeight;
@@ -350,6 +355,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param maxVideoFrameRate Maximum allowed video frame rate in hertz.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxVideoFrameRate(int maxVideoFrameRate) {
       this.maxVideoFrameRate = maxVideoFrameRate;
       return this;
@@ -361,6 +367,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param maxVideoBitrate Maximum allowed video bitrate in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxVideoBitrate(int maxVideoBitrate) {
       this.maxVideoBitrate = maxVideoBitrate;
       return this;
@@ -373,6 +380,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param minVideoHeight Minimum allowed video height in pixels.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMinVideoSize(int minVideoWidth, int minVideoHeight) {
       this.minVideoWidth = minVideoWidth;
       this.minVideoHeight = minVideoHeight;
@@ -385,6 +393,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param minVideoFrameRate Minimum allowed video frame rate in hertz.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMinVideoFrameRate(int minVideoFrameRate) {
       this.minVideoFrameRate = minVideoFrameRate;
       return this;
@@ -396,6 +405,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param minVideoBitrate Minimum allowed video bitrate in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMinVideoBitrate(int minVideoBitrate) {
       this.minVideoBitrate = minVideoBitrate;
       return this;
@@ -410,6 +420,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     playback.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setViewportSizeToPhysicalDisplaySize(
         Context context, boolean viewportOrientationMayChange) {
       // Assume the viewport is fullscreen.
@@ -423,6 +434,7 @@ public class TrackSelectionParameters implements Bundleable {
      *
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder clearViewportSizeConstraints() {
       return setViewportSize(Integer.MAX_VALUE, Integer.MAX_VALUE, true);
     }
@@ -437,6 +449,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     playback.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setViewportSize(
         int viewportWidth, int viewportHeight, boolean viewportOrientationMayChange) {
       this.viewportWidth = viewportWidth;
@@ -463,6 +476,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     empty list for no preference.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredVideoMimeTypes(String... mimeTypes) {
       preferredVideoMimeTypes = ImmutableList.copyOf(mimeTypes);
       return this;
@@ -474,6 +488,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param preferredVideoRoleFlags Preferred video role flags.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredVideoRoleFlags(@C.RoleFlags int preferredVideoRoleFlags) {
       this.preferredVideoRoleFlags = preferredVideoRoleFlags;
       return this;
@@ -502,6 +517,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     there's no default.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredAudioLanguages(String... preferredAudioLanguages) {
       this.preferredAudioLanguages = normalizeLanguageCodes(preferredAudioLanguages);
       return this;
@@ -513,6 +529,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param preferredAudioRoleFlags Preferred audio role flags.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredAudioRoleFlags(@C.RoleFlags int preferredAudioRoleFlags) {
       this.preferredAudioRoleFlags = preferredAudioRoleFlags;
       return this;
@@ -524,6 +541,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param maxAudioChannelCount Maximum allowed audio channel count.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxAudioChannelCount(int maxAudioChannelCount) {
       this.maxAudioChannelCount = maxAudioChannelCount;
       return this;
@@ -535,6 +553,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param maxAudioBitrate Maximum allowed audio bitrate in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxAudioBitrate(int maxAudioBitrate) {
       this.maxAudioBitrate = maxAudioBitrate;
       return this;
@@ -558,6 +577,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     empty list for no preference.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredAudioMimeTypes(String... mimeTypes) {
       preferredAudioMimeTypes = ImmutableList.copyOf(mimeTypes);
       return this;
@@ -574,6 +594,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param context A {@link Context}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredTextLanguageAndRoleFlagsToCaptioningManagerSettings(
         Context context) {
       if (Util.SDK_INT >= 19) {
@@ -603,6 +624,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     track otherwise.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredTextLanguages(String... preferredTextLanguages) {
       this.preferredTextLanguages = normalizeLanguageCodes(preferredTextLanguages);
       return this;
@@ -614,6 +636,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param preferredTextRoleFlags Preferred text role flags.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPreferredTextRoleFlags(@C.RoleFlags int preferredTextRoleFlags) {
       this.preferredTextRoleFlags = preferredTextRoleFlags;
       return this;
@@ -626,6 +649,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     text track selections.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setIgnoredTextSelectionFlags(@C.SelectionFlags int ignoredTextSelectionFlags) {
       this.ignoredTextSelectionFlags = ignoredTextSelectionFlags;
       return this;
@@ -640,6 +664,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     be selected if no preferred language track is available.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSelectUndeterminedTextLanguage(boolean selectUndeterminedTextLanguage) {
       this.selectUndeterminedTextLanguage = selectUndeterminedTextLanguage;
       return this;
@@ -655,6 +680,7 @@ public class TrackSelectionParameters implements Bundleable {
      *     video tracks.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setForceLowestBitrate(boolean forceLowestBitrate) {
       this.forceLowestBitrate = forceLowestBitrate;
       return this;
@@ -668,18 +694,21 @@ public class TrackSelectionParameters implements Bundleable {
      *     and video tracks.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setForceHighestSupportedBitrate(boolean forceHighestSupportedBitrate) {
       this.forceHighestSupportedBitrate = forceHighestSupportedBitrate;
       return this;
     }
 
     /** Adds an override, replacing any override for the same {@link TrackGroup}. */
+    @CanIgnoreReturnValue
     public Builder addOverride(TrackSelectionOverride override) {
       overrides.put(override.mediaTrackGroup, override);
       return this;
     }
 
     /** Sets an override, replacing all existing overrides with the same track type. */
+    @CanIgnoreReturnValue
     public Builder setOverrideForType(TrackSelectionOverride override) {
       clearOverridesOfType(override.getType());
       overrides.put(override.mediaTrackGroup, override);
@@ -687,12 +716,14 @@ public class TrackSelectionParameters implements Bundleable {
     }
 
     /** Removes the override for the provided media {@link TrackGroup}, if there is one. */
+    @CanIgnoreReturnValue
     public Builder clearOverride(TrackGroup mediaTrackGroup) {
       overrides.remove(mediaTrackGroup);
       return this;
     }
 
     /** Removes all overrides of the provided track type. */
+    @CanIgnoreReturnValue
     public Builder clearOverridesOfType(@C.TrackType int trackType) {
       Iterator<TrackSelectionOverride> it = overrides.values().iterator();
       while (it.hasNext()) {
@@ -705,6 +736,7 @@ public class TrackSelectionParameters implements Bundleable {
     }
 
     /** Removes all overrides. */
+    @CanIgnoreReturnValue
     public Builder clearOverrides() {
       overrides.clear();
       return this;
@@ -718,6 +750,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @return This builder.
      * @deprecated Use {@link #setTrackTypeDisabled(int, boolean)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDisabledTrackTypes(Set<@C.TrackType Integer> disabledTrackTypes) {
       this.disabledTrackTypes.clear();
@@ -733,6 +766,7 @@ public class TrackSelectionParameters implements Bundleable {
      * @param disabled Whether the track type should be disabled.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setTrackTypeDisabled(@C.TrackType int trackType, boolean disabled) {
       if (disabled) {
         disabledTrackTypes.add(trackType);

library/common/src/main/java/com/google/android/exoplayer2/ui/AdOverlayInfo.java

@@ -24,6 +24,7 @@ import static java.lang.annotation.ElementType.TYPE_USE;
 import android.view.View;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -76,6 +77,7 @@ public final class AdOverlayInfo {
      *
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setDetailedReason(@Nullable String detailedReason) {
       this.detailedReason = detailedReason;
       return this;

library/common/src/main/java/com/google/android/exoplayer2/util/FlagSet.java

@@ -20,6 +20,7 @@ import static com.google.android.exoplayer2.util.Assertions.checkState;
 
 import android.util.SparseBooleanArray;
 import androidx.annotation.Nullable;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /**
  * A set of integer flags.
@@ -50,6 +51,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder add(int flag) {
       checkState(!buildCalled);
       flags.append(flag, /* value= */ true);
@@ -64,6 +66,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder addIf(int flag, boolean condition) {
       if (condition) {
         return add(flag);
@@ -78,6 +81,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder addAll(int... flags) {
       for (int flag : flags) {
         add(flag);
@@ -92,6 +96,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder addAll(FlagSet flags) {
       for (int i = 0; i < flags.size(); i++) {
         add(flags.get(i));
@@ -106,6 +111,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder remove(int flag) {
       checkState(!buildCalled);
       flags.delete(flag);
@@ -120,6 +126,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder removeIf(int flag, boolean condition) {
       if (condition) {
         return remove(flag);
@@ -134,6 +141,7 @@ public final class FlagSet {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder removeAll(int... flags) {
       for (int flag : flags) {
         remove(flag);

library/common/src/main/java/com/google/android/exoplayer2/util/SystemHandlerWrapper.java

@@ -21,6 +21,7 @@ import android.os.Handler;
 import android.os.Looper;
 import androidx.annotation.GuardedBy;
 import androidx.annotation.Nullable;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -136,6 +137,7 @@ import java.util.List;
     @Nullable private android.os.Message message;
     @Nullable private SystemHandlerWrapper handler;
 
+    @CanIgnoreReturnValue
     public SystemMessage setMessage(android.os.Message message, SystemHandlerWrapper handler) {
       this.message = message;
       this.handler = handler;

library/core/src/main/java/com/google/android/exoplayer2/DefaultLivePlaybackSpeedControl.java

@@ -23,6 +23,7 @@ import android.os.SystemClock;
 import com.google.android.exoplayer2.MediaItem.LiveConfiguration;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /**
  * A {@link LivePlaybackSpeedControl} that adjusts the playback speed using a proportional
@@ -122,6 +123,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      * @param fallbackMinPlaybackSpeed The fallback minimum factor by which playback can be sped up.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setFallbackMinPlaybackSpeed(float fallbackMinPlaybackSpeed) {
       Assertions.checkArgument(0 < fallbackMinPlaybackSpeed && fallbackMinPlaybackSpeed <= 1f);
       this.fallbackMinPlaybackSpeed = fallbackMinPlaybackSpeed;
@@ -137,6 +139,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      * @param fallbackMaxPlaybackSpeed The fallback maximum factor by which playback can be sped up.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setFallbackMaxPlaybackSpeed(float fallbackMaxPlaybackSpeed) {
       Assertions.checkArgument(fallbackMaxPlaybackSpeed >= 1f);
       this.fallbackMaxPlaybackSpeed = fallbackMaxPlaybackSpeed;
@@ -152,6 +155,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      *     milliseconds.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMinUpdateIntervalMs(long minUpdateIntervalMs) {
       Assertions.checkArgument(minUpdateIntervalMs > 0);
       this.minUpdateIntervalMs = minUpdateIntervalMs;
@@ -170,6 +174,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      *     speed.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setProportionalControlFactor(float proportionalControlFactor) {
       Assertions.checkArgument(proportionalControlFactor > 0);
       this.proportionalControlFactorUs = proportionalControlFactor / C.MICROS_PER_SECOND;
@@ -186,6 +191,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      *     used, in milliseconds.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxLiveOffsetErrorMsForUnitSpeed(long maxLiveOffsetErrorMsForUnitSpeed) {
       Assertions.checkArgument(maxLiveOffsetErrorMsForUnitSpeed > 0);
       this.maxLiveOffsetErrorUsForUnitSpeed = Util.msToUs(maxLiveOffsetErrorMsForUnitSpeed);
@@ -200,6 +206,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      *     when the player is rebuffering, in milliseconds
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setTargetLiveOffsetIncrementOnRebufferMs(
         long targetLiveOffsetIncrementOnRebufferMs) {
       Assertions.checkArgument(targetLiveOffsetIncrementOnRebufferMs >= 0);
@@ -222,6 +229,7 @@ public final class DefaultLivePlaybackSpeedControl implements LivePlaybackSpeedC
      * @param minPossibleLiveOffsetSmoothingFactor The smoothing factor. Must be &ge; 0 and &lt; 1.
      * @return This builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMinPossibleLiveOffsetSmoothingFactor(
         float minPossibleLiveOffsetSmoothingFactor) {
       Assertions.checkArgument(

library/core/src/main/java/com/google/android/exoplayer2/DefaultLoadControl.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.upstream.DefaultAllocator;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /** The default {@link LoadControl} implementation. */
 public class DefaultLoadControl implements LoadControl {
@@ -130,6 +131,7 @@ public class DefaultLoadControl implements LoadControl {
      * @return This builder, for convenience.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setAllocator(DefaultAllocator allocator) {
       checkState(!buildCalled);
       this.allocator = allocator;
@@ -151,6 +153,7 @@ public class DefaultLoadControl implements LoadControl {
      * @return This builder, for convenience.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setBufferDurationsMs(
         int minBufferMs,
         int maxBufferMs,
@@ -182,6 +185,7 @@ public class DefaultLoadControl implements LoadControl {
      * @return This builder, for convenience.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setTargetBufferBytes(int targetBufferBytes) {
       checkState(!buildCalled);
       this.targetBufferBytes = targetBufferBytes;
@@ -197,6 +201,7 @@ public class DefaultLoadControl implements LoadControl {
      * @return This builder, for convenience.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setPrioritizeTimeOverSizeThresholds(boolean prioritizeTimeOverSizeThresholds) {
       checkState(!buildCalled);
       this.prioritizeTimeOverSizeThresholds = prioritizeTimeOverSizeThresholds;
@@ -213,6 +218,7 @@ public class DefaultLoadControl implements LoadControl {
      * @return This builder, for convenience.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setBackBuffer(int backBufferDurationMs, boolean retainBackBufferFromKeyframe) {
       checkState(!buildCalled);
       assertGreaterOrEqual(backBufferDurationMs, 0, "backBufferDurationMs", "0");

library/core/src/main/java/com/google/android/exoplayer2/DefaultRenderersFactory.java

@@ -41,6 +41,7 @@ import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.video.MediaCodecVideoRenderer;
 import com.google.android.exoplayer2.video.VideoRendererEventListener;
 import com.google.android.exoplayer2.video.spherical.CameraMotionRenderer;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -122,6 +123,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    * @param extensionRendererMode The extension renderer mode.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setExtensionRendererMode(
       @ExtensionRendererMode int extensionRendererMode) {
     this.extensionRendererMode = extensionRendererMode;
@@ -137,6 +139,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory forceEnableMediaCodecAsynchronousQueueing() {
     codecAdapterFactory.forceEnableAsynchronous();
     return this;
@@ -149,6 +152,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory forceDisableMediaCodecAsynchronousQueueing() {
     codecAdapterFactory.forceDisableAsynchronous();
     return this;
@@ -163,6 +167,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *     queueing.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory experimentalSetSynchronizeCodecInteractionsWithQueueingEnabled(
       boolean enabled) {
     codecAdapterFactory.experimentalSetSynchronizeCodecInteractionsWithQueueingEnabled(enabled);
@@ -177,6 +182,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *     initialization fails.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setEnableDecoderFallback(boolean enableDecoderFallback) {
     this.enableDecoderFallback = enableDecoderFallback;
     return this;
@@ -190,6 +196,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    * @param mediaCodecSelector The {@link MediaCodecSelector}.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setMediaCodecSelector(MediaCodecSelector mediaCodecSelector) {
     this.mediaCodecSelector = mediaCodecSelector;
     return this;
@@ -206,6 +213,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    * @param enableFloatOutput Whether to enable use of floating point audio output, if available.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setEnableAudioFloatOutput(boolean enableFloatOutput) {
     this.enableFloatOutput = enableFloatOutput;
     return this;
@@ -228,6 +236,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *     available.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setEnableAudioOffload(boolean enableOffload) {
     this.enableOffload = enableOffload;
     return this;
@@ -251,6 +260,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *     android.media.AudioTrack#setPlaybackParams(PlaybackParams)}.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setEnableAudioTrackPlaybackParams(
       boolean enableAudioTrackPlaybackParams) {
     this.enableAudioTrackPlaybackParams = enableAudioTrackPlaybackParams;
@@ -267,6 +277,7 @@ public class DefaultRenderersFactory implements RenderersFactory {
    *     seamlessly join an ongoing playback, in milliseconds.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultRenderersFactory setAllowedVideoJoiningTimeMs(long allowedVideoJoiningTimeMs) {
     this.allowedVideoJoiningTimeMs = allowedVideoJoiningTimeMs;
     return this;

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayer.java

@@ -63,6 +63,7 @@ import com.google.android.exoplayer2.video.VideoSize;
 import com.google.android.exoplayer2.video.spherical.CameraMotionListener;
 import com.google.common.base.Function;
 import com.google.common.base.Supplier;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.List;
 
 /**
@@ -667,6 +668,7 @@ public interface ExoPlayer extends Player {
      *
      * @param timeoutMs The time limit in milliseconds.
      */
+    @CanIgnoreReturnValue
     public Builder experimentalSetForegroundModeTimeoutMs(long timeoutMs) {
       checkState(!buildCalled);
       foregroundModeTimeoutMs = timeoutMs;
@@ -680,6 +682,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setRenderersFactory(RenderersFactory renderersFactory) {
       checkState(!buildCalled);
       checkNotNull(renderersFactory);
@@ -694,6 +697,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSourceFactory(MediaSource.Factory mediaSourceFactory) {
       checkState(!buildCalled);
       checkNotNull(mediaSourceFactory);
@@ -708,6 +712,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setTrackSelector(TrackSelector trackSelector) {
       checkState(!buildCalled);
       checkNotNull(trackSelector);
@@ -722,6 +727,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setLoadControl(LoadControl loadControl) {
       checkState(!buildCalled);
       checkNotNull(loadControl);
@@ -736,6 +742,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setBandwidthMeter(BandwidthMeter bandwidthMeter) {
       checkState(!buildCalled);
       checkNotNull(bandwidthMeter);
@@ -751,6 +758,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setLooper(Looper looper) {
       checkState(!buildCalled);
       checkNotNull(looper);
@@ -765,6 +773,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setAnalyticsCollector(AnalyticsCollector analyticsCollector) {
       checkState(!buildCalled);
       checkNotNull(analyticsCollector);
@@ -781,6 +790,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setPriorityTaskManager(@Nullable PriorityTaskManager priorityTaskManager) {
       checkState(!buildCalled);
       this.priorityTaskManager = priorityTaskManager;
@@ -800,6 +810,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioAttributes(AudioAttributes audioAttributes, boolean handleAudioFocus) {
       checkState(!buildCalled);
       this.audioAttributes = checkNotNull(audioAttributes);
@@ -824,6 +835,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setWakeMode(@C.WakeMode int wakeMode) {
       checkState(!buildCalled);
       this.wakeMode = wakeMode;
@@ -841,6 +853,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setHandleAudioBecomingNoisy(boolean handleAudioBecomingNoisy) {
       checkState(!buildCalled);
       this.handleAudioBecomingNoisy = handleAudioBecomingNoisy;
@@ -854,6 +867,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setSkipSilenceEnabled(boolean skipSilenceEnabled) {
       checkState(!buildCalled);
       this.skipSilenceEnabled = skipSilenceEnabled;
@@ -870,6 +884,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoScalingMode(@C.VideoScalingMode int videoScalingMode) {
       checkState(!buildCalled);
       this.videoScalingMode = videoScalingMode;
@@ -890,6 +905,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoChangeFrameRateStrategy(
         @C.VideoChangeFrameRateStrategy int videoChangeFrameRateStrategy) {
       checkState(!buildCalled);
@@ -908,6 +924,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setUseLazyPreparation(boolean useLazyPreparation) {
       checkState(!buildCalled);
       this.useLazyPreparation = useLazyPreparation;
@@ -921,6 +938,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setSeekParameters(SeekParameters seekParameters) {
       checkState(!buildCalled);
       this.seekParameters = checkNotNull(seekParameters);
@@ -935,6 +953,7 @@ public interface ExoPlayer extends Player {
      * @throws IllegalArgumentException If {@code seekBackIncrementMs} is non-positive.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setSeekBackIncrementMs(@IntRange(from = 1) long seekBackIncrementMs) {
       checkArgument(seekBackIncrementMs > 0);
       checkState(!buildCalled);
@@ -950,6 +969,7 @@ public interface ExoPlayer extends Player {
      * @throws IllegalArgumentException If {@code seekForwardIncrementMs} is non-positive.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setSeekForwardIncrementMs(@IntRange(from = 1) long seekForwardIncrementMs) {
       checkArgument(seekForwardIncrementMs > 0);
       checkState(!buildCalled);
@@ -968,6 +988,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setReleaseTimeoutMs(long releaseTimeoutMs) {
       checkState(!buildCalled);
       this.releaseTimeoutMs = releaseTimeoutMs;
@@ -985,6 +1006,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setDetachSurfaceTimeoutMs(long detachSurfaceTimeoutMs) {
       checkState(!buildCalled);
       this.detachSurfaceTimeoutMs = detachSurfaceTimeoutMs;
@@ -1003,6 +1025,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setPauseAtEndOfMediaItems(boolean pauseAtEndOfMediaItems) {
       checkState(!buildCalled);
       this.pauseAtEndOfMediaItems = pauseAtEndOfMediaItems;
@@ -1017,6 +1040,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setLivePlaybackSpeedControl(LivePlaybackSpeedControl livePlaybackSpeedControl) {
       checkState(!buildCalled);
       this.livePlaybackSpeedControl = checkNotNull(livePlaybackSpeedControl);
@@ -1038,6 +1062,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     public Builder setUsePlatformDiagnostics(boolean usePlatformDiagnostics) {
       checkState(!buildCalled);
       this.usePlatformDiagnostics = usePlatformDiagnostics;
@@ -1052,6 +1077,7 @@ public interface ExoPlayer extends Player {
      * @return This builder.
      * @throws IllegalStateException If {@link #build()} has already been called.
      */
+    @CanIgnoreReturnValue
     @VisibleForTesting
     public Builder setClock(Clock clock) {
       checkState(!buildCalled);

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImpl.java

@@ -94,6 +94,7 @@ import com.google.android.exoplayer2.video.VideoSize;
 import com.google.android.exoplayer2.video.spherical.CameraMotionListener;
 import com.google.android.exoplayer2.video.spherical.SphericalGLSurfaceView;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -386,6 +387,7 @@ import java.util.concurrent.TimeoutException;
     }
   }
 
+  @CanIgnoreReturnValue
   @SuppressWarnings("deprecation") // Returning deprecated class.
   @Override
   @Deprecated
@@ -394,6 +396,7 @@ import java.util.concurrent.TimeoutException;
     return this;
   }
 
+  @CanIgnoreReturnValue
   @SuppressWarnings("deprecation") // Returning deprecated class.
   @Override
   @Deprecated
@@ -402,6 +405,7 @@ import java.util.concurrent.TimeoutException;
     return this;
   }
 
+  @CanIgnoreReturnValue
   @SuppressWarnings("deprecation") // Returning deprecated class.
   @Override
   @Deprecated
@@ -410,6 +414,7 @@ import java.util.concurrent.TimeoutException;
     return this;
   }
 
+  @CanIgnoreReturnValue
   @SuppressWarnings("deprecation") // Returning deprecated class.
   @Override
   @Deprecated

library/core/src/main/java/com/google/android/exoplayer2/PlayerMessage.java

@@ -21,6 +21,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.Renderer.MessageType;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Clock;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.concurrent.TimeoutException;
 
 /**
@@ -118,6 +119,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setType(int messageType) {
     Assertions.checkState(!isSent);
     this.type = messageType;
@@ -136,6 +138,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setPayload(@Nullable Object payload) {
     Assertions.checkState(!isSent);
     this.payload = payload;
@@ -151,6 +154,7 @@ public final class PlayerMessage {
   /**
    * @deprecated Use {@link #setLooper(Looper)} instead.
    */
+  @CanIgnoreReturnValue
   @Deprecated
   public PlayerMessage setHandler(Handler handler) {
     return setLooper(handler.getLooper());
@@ -163,6 +167,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setLooper(Looper looper) {
     Assertions.checkState(!isSent);
     this.looper = looper;
@@ -193,6 +198,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setPosition(long positionMs) {
     Assertions.checkState(!isSent);
     this.positionMs = positionMs;
@@ -211,6 +217,7 @@ public final class PlayerMessage {
    *     empty and the provided media item index is not within the bounds of the timeline.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setPosition(int mediaItemIndex, long positionMs) {
     Assertions.checkState(!isSent);
     Assertions.checkArgument(positionMs != C.TIME_UNSET);
@@ -237,6 +244,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If {@link #send()} has already been called.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage setDeleteAfterDelivery(boolean deleteAfterDelivery) {
     Assertions.checkState(!isSent);
     this.deleteAfterDelivery = deleteAfterDelivery;
@@ -255,6 +263,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If this message has already been sent.
    */
+  @CanIgnoreReturnValue
   public PlayerMessage send() {
     Assertions.checkState(!isSent);
     if (positionMs == C.TIME_UNSET) {
@@ -271,6 +280,7 @@ public final class PlayerMessage {
    * @return This message.
    * @throws IllegalStateException If this method is called before {@link #send()}.
    */
+  @CanIgnoreReturnValue
   public synchronized PlayerMessage cancel() {
     Assertions.checkState(isSent);
     isCanceled = true;

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -45,6 +45,7 @@ import com.google.android.exoplayer2.util.PriorityTaskManager;
 import com.google.android.exoplayer2.video.VideoFrameMetadataListener;
 import com.google.android.exoplayer2.video.VideoSize;
 import com.google.android.exoplayer2.video.spherical.CameraMotionListener;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.List;
 
 /**
@@ -135,6 +136,7 @@ public class SimpleExoPlayer extends BasePlayer
      * @deprecated Use {@link ExoPlayer.Builder#experimentalSetForegroundModeTimeoutMs(long)}
      *     instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder experimentalSetForegroundModeTimeoutMs(long timeoutMs) {
       wrappedBuilder.experimentalSetForegroundModeTimeoutMs(timeoutMs);
@@ -144,6 +146,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setTrackSelector(TrackSelector)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setTrackSelector(TrackSelector trackSelector) {
       wrappedBuilder.setTrackSelector(trackSelector);
@@ -153,6 +156,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setMediaSourceFactory(MediaSource.Factory)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setMediaSourceFactory(MediaSource.Factory mediaSourceFactory) {
       wrappedBuilder.setMediaSourceFactory(mediaSourceFactory);
@@ -162,6 +166,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setLoadControl(LoadControl)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLoadControl(LoadControl loadControl) {
       wrappedBuilder.setLoadControl(loadControl);
@@ -171,6 +176,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setBandwidthMeter(BandwidthMeter)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setBandwidthMeter(BandwidthMeter bandwidthMeter) {
       wrappedBuilder.setBandwidthMeter(bandwidthMeter);
@@ -180,6 +186,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setLooper(Looper)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLooper(Looper looper) {
       wrappedBuilder.setLooper(looper);
@@ -189,6 +196,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setAnalyticsCollector(AnalyticsCollector)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setAnalyticsCollector(AnalyticsCollector analyticsCollector) {
       wrappedBuilder.setAnalyticsCollector(analyticsCollector);
@@ -199,6 +207,7 @@ public class SimpleExoPlayer extends BasePlayer
      * @deprecated Use {@link ExoPlayer.Builder#setPriorityTaskManager(PriorityTaskManager)}
      *     instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setPriorityTaskManager(@Nullable PriorityTaskManager priorityTaskManager) {
       wrappedBuilder.setPriorityTaskManager(priorityTaskManager);
@@ -209,6 +218,7 @@ public class SimpleExoPlayer extends BasePlayer
      * @deprecated Use {@link ExoPlayer.Builder#setAudioAttributes(AudioAttributes, boolean)}
      *     instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setAudioAttributes(AudioAttributes audioAttributes, boolean handleAudioFocus) {
       wrappedBuilder.setAudioAttributes(audioAttributes, handleAudioFocus);
@@ -218,6 +228,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setWakeMode(int)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setWakeMode(@C.WakeMode int wakeMode) {
       wrappedBuilder.setWakeMode(wakeMode);
@@ -227,6 +238,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setHandleAudioBecomingNoisy(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setHandleAudioBecomingNoisy(boolean handleAudioBecomingNoisy) {
       wrappedBuilder.setHandleAudioBecomingNoisy(handleAudioBecomingNoisy);
@@ -236,6 +248,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setSkipSilenceEnabled(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setSkipSilenceEnabled(boolean skipSilenceEnabled) {
       wrappedBuilder.setSkipSilenceEnabled(skipSilenceEnabled);
@@ -245,6 +258,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setVideoScalingMode(int)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setVideoScalingMode(@C.VideoScalingMode int videoScalingMode) {
       wrappedBuilder.setVideoScalingMode(videoScalingMode);
@@ -254,6 +268,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setVideoChangeFrameRateStrategy(int)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setVideoChangeFrameRateStrategy(
         @C.VideoChangeFrameRateStrategy int videoChangeFrameRateStrategy) {
@@ -264,6 +279,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setUseLazyPreparation(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setUseLazyPreparation(boolean useLazyPreparation) {
       wrappedBuilder.setUseLazyPreparation(useLazyPreparation);
@@ -273,6 +289,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setSeekParameters(SeekParameters)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setSeekParameters(SeekParameters seekParameters) {
       wrappedBuilder.setSeekParameters(seekParameters);
@@ -282,6 +299,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setSeekBackIncrementMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setSeekBackIncrementMs(@IntRange(from = 1) long seekBackIncrementMs) {
       wrappedBuilder.setSeekBackIncrementMs(seekBackIncrementMs);
@@ -291,6 +309,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setSeekForwardIncrementMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setSeekForwardIncrementMs(@IntRange(from = 1) long seekForwardIncrementMs) {
       wrappedBuilder.setSeekForwardIncrementMs(seekForwardIncrementMs);
@@ -300,6 +319,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setReleaseTimeoutMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setReleaseTimeoutMs(long releaseTimeoutMs) {
       wrappedBuilder.setReleaseTimeoutMs(releaseTimeoutMs);
@@ -309,6 +329,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setDetachSurfaceTimeoutMs(long)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setDetachSurfaceTimeoutMs(long detachSurfaceTimeoutMs) {
       wrappedBuilder.setDetachSurfaceTimeoutMs(detachSurfaceTimeoutMs);
@@ -318,6 +339,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setPauseAtEndOfMediaItems(boolean)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setPauseAtEndOfMediaItems(boolean pauseAtEndOfMediaItems) {
       wrappedBuilder.setPauseAtEndOfMediaItems(pauseAtEndOfMediaItems);
@@ -328,6 +350,7 @@ public class SimpleExoPlayer extends BasePlayer
      * @deprecated Use {@link
      *     ExoPlayer.Builder#setLivePlaybackSpeedControl(LivePlaybackSpeedControl)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setLivePlaybackSpeedControl(LivePlaybackSpeedControl livePlaybackSpeedControl) {
       wrappedBuilder.setLivePlaybackSpeedControl(livePlaybackSpeedControl);
@@ -337,6 +360,7 @@ public class SimpleExoPlayer extends BasePlayer
     /**
      * @deprecated Use {@link ExoPlayer.Builder#setClock(Clock)} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     @VisibleForTesting
     public Builder setClock(Clock clock) {

library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java

@@ -48,6 +48,7 @@ import com.google.android.exoplayer2.util.ConditionVariable;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import com.google.errorprone.annotations.InlineMe;
 import com.google.errorprone.annotations.InlineMeValidationDisabled;
 import java.lang.annotation.Documented;
@@ -277,6 +278,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>Default is {@link AudioCapabilities#DEFAULT_AUDIO_CAPABILITIES}.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioCapabilities(AudioCapabilities audioCapabilities) {
       checkNotNull(audioCapabilities);
       this.audioCapabilities = audioCapabilities;
@@ -290,6 +292,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>The default value is an empty array.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioProcessors(AudioProcessor[] audioProcessors) {
       checkNotNull(audioProcessors);
       return setAudioProcessorChain(new DefaultAudioProcessorChain(audioProcessors));
@@ -302,6 +305,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>By default, no processing will be applied.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioProcessorChain(AudioProcessorChain audioProcessorChain) {
       checkNotNull(audioProcessorChain);
       this.audioProcessorChain = audioProcessorChain;
@@ -316,6 +320,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>The default value is {@code false}.
      */
+    @CanIgnoreReturnValue
     public Builder setEnableFloatOutput(boolean enableFloatOutput) {
       this.enableFloatOutput = enableFloatOutput;
       return this;
@@ -329,6 +334,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>The default value is {@code false}.
      */
+    @CanIgnoreReturnValue
     public Builder setEnableAudioTrackPlaybackParams(boolean enableAudioTrackPlaybackParams) {
       this.enableAudioTrackPlaybackParams = enableAudioTrackPlaybackParams;
       return this;
@@ -344,6 +350,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>The default value is {@link #OFFLOAD_MODE_DISABLED}.
      */
+    @CanIgnoreReturnValue
     public Builder setOffloadMode(@OffloadMode int offloadMode) {
       this.offloadMode = offloadMode;
       return this;
@@ -355,6 +362,7 @@ public final class DefaultAudioSink implements AudioSink {
      *
      * <p>The default value is {@link AudioTrackBufferSizeProvider#DEFAULT}.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioTrackBufferSizeProvider(
         AudioTrackBufferSizeProvider audioTrackBufferSizeProvider) {
       this.audioTrackBufferSizeProvider = audioTrackBufferSizeProvider;

library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioTrackBufferSizeProvider.java

@@ -26,6 +26,7 @@ import android.media.AudioTrack;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.audio.DefaultAudioSink.OutputMode;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /** Provide the buffer size to use when creating an {@link AudioTrack}. */
 public class DefaultAudioTrackBufferSizeProvider
@@ -71,6 +72,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * Sets the minimum length for PCM {@link AudioTrack} buffers, in microseconds. Default is
      * {@value #MIN_PCM_BUFFER_DURATION_US}.
      */
+    @CanIgnoreReturnValue
     public Builder setMinPcmBufferDurationUs(int minPcmBufferDurationUs) {
       this.minPcmBufferDurationUs = minPcmBufferDurationUs;
       return this;
@@ -80,6 +82,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * Sets the maximum length for PCM {@link AudioTrack} buffers, in microseconds. Default is
      * {@value #MAX_PCM_BUFFER_DURATION_US}.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxPcmBufferDurationUs(int maxPcmBufferDurationUs) {
       this.maxPcmBufferDurationUs = maxPcmBufferDurationUs;
       return this;
@@ -89,6 +92,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * Sets the multiplication factor to apply to the minimum buffer size requested. Default is
      * {@value #PCM_BUFFER_MULTIPLICATION_FACTOR}.
      */
+    @CanIgnoreReturnValue
     public Builder setPcmBufferMultiplicationFactor(int pcmBufferMultiplicationFactor) {
       this.pcmBufferMultiplicationFactor = pcmBufferMultiplicationFactor;
       return this;
@@ -98,6 +102,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * Sets the length for passthrough {@link AudioTrack} buffers, in microseconds. Default is
      * {@value #PASSTHROUGH_BUFFER_DURATION_US}.
      */
+    @CanIgnoreReturnValue
     public Builder setPassthroughBufferDurationUs(int passthroughBufferDurationUs) {
       this.passthroughBufferDurationUs = passthroughBufferDurationUs;
       return this;
@@ -107,6 +112,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * The length for offload {@link AudioTrack} buffers, in microseconds. Default is {@value
      * #OFFLOAD_BUFFER_DURATION_US}.
      */
+    @CanIgnoreReturnValue
     public Builder setOffloadBufferDurationUs(int offloadBufferDurationUs) {
       this.offloadBufferDurationUs = offloadBufferDurationUs;
       return this;
@@ -116,6 +122,7 @@ public class DefaultAudioTrackBufferSizeProvider
      * Sets the multiplication factor to apply to the passthrough buffer for AC3 to avoid underruns
      * on some devices (e.g., Broadcom 7271). Default is {@value #AC3_BUFFER_MULTIPLICATION_FACTOR}.
      */
+    @CanIgnoreReturnValue
     public Builder setAc3BufferMultiplicationFactor(int ac3BufferMultiplicationFactor) {
       this.ac3BufferMultiplicationFactor = ac3BufferMultiplicationFactor;
       return this;

library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java

@@ -45,6 +45,7 @@ import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -118,6 +119,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      * @param keyRequestParameters A map with parameters.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setKeyRequestParameters(@Nullable Map<String, String> keyRequestParameters) {
       this.keyRequestParameters.clear();
       if (keyRequestParameters != null) {
@@ -133,6 +135,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      * @param exoMediaDrmProvider The {@link ExoMediaDrm.Provider}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUuidAndExoMediaDrmProvider(
         UUID uuid, ExoMediaDrm.Provider exoMediaDrmProvider) {
       this.uuid = checkNotNull(uuid);
@@ -150,6 +153,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      *     sessions.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMultiSession(boolean multiSession) {
       this.multiSession = multiSession;
       return this;
@@ -169,6 +173,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      * @throws IllegalArgumentException If {@code useDrmSessionsForClearContentTrackTypes} contains
      *     track types other than {@link C#TRACK_TYPE_AUDIO} and {@link C#TRACK_TYPE_VIDEO}.
      */
+    @CanIgnoreReturnValue
     public Builder setUseDrmSessionsForClearContent(
         @C.TrackType int... useDrmSessionsForClearContentTrackTypes) {
       for (@C.TrackType int trackType : useDrmSessionsForClearContentTrackTypes) {
@@ -187,6 +192,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      *     played when keys for the encrypted part of the content have yet to be loaded.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPlayClearSamplesWithoutKeys(boolean playClearSamplesWithoutKeys) {
       this.playClearSamplesWithoutKeys = playClearSamplesWithoutKeys;
       return this;
@@ -198,6 +204,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      * @param loadErrorHandlingPolicy A {@link LoadErrorHandlingPolicy}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy = checkNotNull(loadErrorHandlingPolicy);
       return this;
@@ -218,6 +225,7 @@ public class DefaultDrmSessionManager implements DrmSessionManager {
      *     in milliseconds. Must be &gt; 0 or {@link C#TIME_UNSET} to disable keep-alive.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSessionKeepaliveMs(long sessionKeepaliveMs) {
       checkArgument(sessionKeepaliveMs > 0 || sessionKeepaliveMs == C.TIME_UNSET);
       this.sessionKeepaliveMs = sessionKeepaliveMs;

library/core/src/main/java/com/google/android/exoplayer2/mediacodec/DefaultMediaCodecAdapterFactory.java

@@ -21,6 +21,7 @@ import androidx.annotation.IntDef;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
@@ -64,6 +65,7 @@ public final class DefaultMediaCodecAdapterFactory implements MediaCodecAdapter.
    *
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaCodecAdapterFactory forceEnableAsynchronous() {
     asynchronousMode = MODE_ENABLED;
     return this;
@@ -74,6 +76,7 @@ public final class DefaultMediaCodecAdapterFactory implements MediaCodecAdapter.
    *
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaCodecAdapterFactory forceDisableAsynchronous() {
     asynchronousMode = MODE_DISABLED;
     return this;

library/core/src/main/java/com/google/android/exoplayer2/offline/DownloadRequest.java

@@ -26,6 +26,7 @@ import com.google.android.exoplayer2.MediaItem;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -55,30 +56,35 @@ public final class DownloadRequest implements Parcelable {
     }
 
     /** Sets the {@link DownloadRequest#mimeType}. */
+    @CanIgnoreReturnValue
     public Builder setMimeType(@Nullable String mimeType) {
       this.mimeType = mimeType;
       return this;
     }
 
     /** Sets the {@link DownloadRequest#streamKeys}. */
+    @CanIgnoreReturnValue
     public Builder setStreamKeys(@Nullable List<StreamKey> streamKeys) {
       this.streamKeys = streamKeys;
       return this;
     }
 
     /** Sets the {@link DownloadRequest#keySetId}. */
+    @CanIgnoreReturnValue
     public Builder setKeySetId(@Nullable byte[] keySetId) {
       this.keySetId = keySetId;
       return this;
     }
 
     /** Sets the {@link DownloadRequest#customCacheKey}. */
+    @CanIgnoreReturnValue
     public Builder setCustomCacheKey(@Nullable String customCacheKey) {
       this.customCacheKey = customCacheKey;
       return this;
     }
 
     /** Sets the {@link DownloadRequest#data}. */
+    @CanIgnoreReturnValue
     public Builder setData(@Nullable byte[] data) {
       this.data = data;
       return this;

library/core/src/main/java/com/google/android/exoplayer2/source/DefaultMediaSourceFactory.java

@@ -50,6 +50,7 @@ import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Supplier;
 import com.google.common.collect.ImmutableList;
 import com.google.common.primitives.Ints;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -190,6 +191,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     should be used for subtitles instead of {@link SingleSampleMediaSource}.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory experimentalUseProgressiveMediaSourceForSubtitles(
       boolean useProgressiveMediaSourceForSubtitles) {
     this.useProgressiveMediaSourceForSubtitles = useProgressiveMediaSourceForSubtitles;
@@ -208,6 +210,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    * @deprecated Use {@link #setLocalAdInsertionComponents(AdsLoader.Provider, AdViewProvider)}
    *     instead.
    */
+  @CanIgnoreReturnValue
   @Deprecated
   public DefaultMediaSourceFactory setAdsLoaderProvider(
       @Nullable AdsLoader.Provider adsLoaderProvider) {
@@ -226,6 +229,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    * @deprecated Use {@link #setLocalAdInsertionComponents(AdsLoader.Provider, AdViewProvider)}
    *     instead.
    */
+  @CanIgnoreReturnValue
   @Deprecated
   public DefaultMediaSourceFactory setAdViewProvider(@Nullable AdViewProvider adViewProvider) {
     this.adViewProvider = adViewProvider;
@@ -243,6 +247,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    * @param adViewProvider A provider for information about views for the ad playback UI.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLocalAdInsertionComponents(
       AdsLoader.Provider adsLoaderProvider, AdViewProvider adViewProvider) {
     this.adsLoaderProvider = checkNotNull(adsLoaderProvider);
@@ -259,6 +264,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory clearLocalAdInsertionComponents() {
     this.adsLoaderProvider = null;
     this.adViewProvider = null;
@@ -272,6 +278,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    * @param dataSourceFactory The {@link DataSource.Factory}.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setDataSourceFactory(DataSource.Factory dataSourceFactory) {
     this.dataSourceFactory = dataSourceFactory;
     delegateFactoryLoader.setDataSourceFactory(dataSourceFactory);
@@ -288,6 +295,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     content, or {@code null} to remove a previously set {@link MediaSource.Factory}.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setServerSideAdInsertionMediaSourceFactory(
       @Nullable MediaSource.Factory serverSideAdInsertionMediaSourceFactory) {
     this.serverSideAdInsertionMediaSourceFactory = serverSideAdInsertionMediaSourceFactory;
@@ -301,6 +309,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     use the media-defined default.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLiveTargetOffsetMs(long liveTargetOffsetMs) {
     this.liveTargetOffsetMs = liveTargetOffsetMs;
     return this;
@@ -313,6 +322,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     C#TIME_UNSET} to use the media-defined default.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLiveMinOffsetMs(long liveMinOffsetMs) {
     this.liveMinOffsetMs = liveMinOffsetMs;
     return this;
@@ -325,6 +335,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     C#TIME_UNSET} to use the media-defined default.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLiveMaxOffsetMs(long liveMaxOffsetMs) {
     this.liveMaxOffsetMs = liveMaxOffsetMs;
     return this;
@@ -337,6 +348,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     C#RATE_UNSET} to use the media-defined default.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLiveMinSpeed(float minSpeed) {
     this.liveMinSpeed = minSpeed;
     return this;
@@ -349,11 +361,13 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
    *     C#RATE_UNSET} to use the media-defined default.
    * @return This factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public DefaultMediaSourceFactory setLiveMaxSpeed(float maxSpeed) {
     this.liveMaxSpeed = maxSpeed;
     return this;
   }
 
+  @CanIgnoreReturnValue
   @Override
   public DefaultMediaSourceFactory setDrmSessionManagerProvider(
       DrmSessionManagerProvider drmSessionManagerProvider) {
@@ -366,6 +380,7 @@ public final class DefaultMediaSourceFactory implements MediaSourceFactory {
     return this;
   }
 
+  @CanIgnoreReturnValue
   @Override
   public DefaultMediaSourceFactory setLoadErrorHandlingPolicy(
       LoadErrorHandlingPolicy loadErrorHandlingPolicy) {

library/core/src/main/java/com/google/android/exoplayer2/source/ProgressiveMediaSource.java

@@ -34,6 +34,7 @@ import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DefaultLoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.TransferListener;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /**
  * Provides one period that loads data from a {@link Uri} and extracted using an {@link Extractor}.
@@ -153,6 +154,7 @@ public final class ProgressiveMediaSource extends BaseMediaSource
       this.continueLoadingCheckIntervalBytes = continueLoadingCheckIntervalBytes;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy =
@@ -174,11 +176,13 @@ public final class ProgressiveMediaSource extends BaseMediaSource
      *     MediaPeriod.Callback#onContinueLoadingRequested(SequenceableLoader)}.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setContinueLoadingCheckIntervalBytes(int continueLoadingCheckIntervalBytes) {
       this.continueLoadingCheckIntervalBytes = continueLoadingCheckIntervalBytes;
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setDrmSessionManagerProvider(
         DrmSessionManagerProvider drmSessionManagerProvider) {

library/core/src/main/java/com/google/android/exoplayer2/source/SilenceMediaSource.java

@@ -33,6 +33,7 @@ import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import org.checkerframework.checker.nullness.compatqual.NullableType;
 
@@ -51,6 +52,7 @@ public final class SilenceMediaSource extends BaseMediaSource {
      * @param durationUs The duration of silent audio to output, in microseconds.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setDurationUs(@IntRange(from = 1) long durationUs) {
       this.durationUs = durationUs;
       return this;
@@ -63,6 +65,7 @@ public final class SilenceMediaSource extends BaseMediaSource {
      * @param tag A tag for the media source.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setTag(@Nullable Object tag) {
       this.tag = tag;
       return this;

library/core/src/main/java/com/google/android/exoplayer2/source/SingleSampleMediaSource.java

@@ -31,6 +31,7 @@ import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /**
  * Loads data at a given {@link Uri} as a single sample belonging to a single {@link MediaPeriod}.
@@ -66,6 +67,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
      * @param tag A tag for the media source.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setTag(@Nullable Object tag) {
       this.tag = tag;
       return this;
@@ -77,6 +79,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
      *     #createMediaSource(MediaItem.SubtitleConfiguration, long)}). {@code trackId} will only be
      *     used if {@link MediaItem.SubtitleConfiguration#id} is {@code null}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Factory setTrackId(@Nullable String trackId) {
       this.trackId = trackId;
@@ -90,6 +93,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
      * @param loadErrorHandlingPolicy A {@link LoadErrorHandlingPolicy}.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setLoadErrorHandlingPolicy(
         @Nullable LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy =
@@ -108,6 +112,7 @@ public final class SingleSampleMediaSource extends BaseMediaSource {
      *     normally by {@link SampleStream#maybeThrowError()}.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setTreatLoadErrorsAsEndOfStream(boolean treatLoadErrorsAsEndOfStream) {
       this.treatLoadErrorsAsEndOfStream = treatLoadErrorsAsEndOfStream;
       return this;

library/core/src/main/java/com/google/android/exoplayer2/trackselection/DefaultTrackSelector.java

@@ -63,6 +63,7 @@ import com.google.common.collect.ComparisonChain;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Ordering;
 import com.google.common.primitives.Ints;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -141,6 +142,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       delegate = new Parameters.Builder(context);
     }
 
+    @CanIgnoreReturnValue
     @Override
     protected ParametersBuilder set(TrackSelectionParameters parameters) {
       delegate.set(parameters);
@@ -149,18 +151,21 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
     // Video
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMaxVideoSizeSd() {
       delegate.setMaxVideoSizeSd();
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder clearVideoSizeConstraints() {
       delegate.clearVideoSizeConstraints();
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMaxVideoSize(
         int maxVideoWidth, int maxVideoHeight) {
@@ -168,18 +173,21 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMaxVideoFrameRate(int maxVideoFrameRate) {
       delegate.setMaxVideoFrameRate(maxVideoFrameRate);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMaxVideoBitrate(int maxVideoBitrate) {
       delegate.setMaxVideoBitrate(maxVideoBitrate);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMinVideoSize(
         int minVideoWidth, int minVideoHeight) {
@@ -187,12 +195,14 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMinVideoFrameRate(int minVideoFrameRate) {
       delegate.setMinVideoFrameRate(minVideoFrameRate);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setMinVideoBitrate(int minVideoBitrate) {
       delegate.setMinVideoBitrate(minVideoBitrate);
@@ -207,6 +217,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     selection can be made otherwise.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setExceedVideoConstraintsIfNecessary(
         boolean exceedVideoConstraintsIfNecessary) {
       delegate.setExceedVideoConstraintsIfNecessary(exceedVideoConstraintsIfNecessary);
@@ -224,6 +235,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     containing mixed MIME types.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowVideoMixedMimeTypeAdaptiveness(
         boolean allowVideoMixedMimeTypeAdaptiveness) {
       delegate.setAllowVideoMixedMimeTypeAdaptiveness(allowVideoMixedMimeTypeAdaptiveness);
@@ -238,6 +250,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     adaptation may not be completely seamless.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowVideoNonSeamlessAdaptiveness(
         boolean allowVideoNonSeamlessAdaptiveness) {
       delegate.setAllowVideoNonSeamlessAdaptiveness(allowVideoNonSeamlessAdaptiveness);
@@ -253,6 +266,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     with mixed levels of decoder and hardware acceleration support.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowVideoMixedDecoderSupportAdaptiveness(
         boolean allowVideoMixedDecoderSupportAdaptiveness) {
       delegate.setAllowVideoMixedDecoderSupportAdaptiveness(
@@ -260,6 +274,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setViewportSizeToPhysicalDisplaySize(
         Context context, boolean viewportOrientationMayChange) {
@@ -267,12 +282,14 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder clearViewportSizeConstraints() {
       delegate.clearViewportSizeConstraints();
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setViewportSize(
         int viewportWidth, int viewportHeight, boolean viewportOrientationMayChange) {
@@ -280,18 +297,21 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredVideoMimeType(@Nullable String mimeType) {
       delegate.setPreferredVideoMimeType(mimeType);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredVideoMimeTypes(String... mimeTypes) {
       delegate.setPreferredVideoMimeTypes(mimeTypes);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public DefaultTrackSelector.ParametersBuilder setPreferredVideoRoleFlags(
         @RoleFlags int preferredVideoRoleFlags) {
@@ -301,30 +321,35 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
     // Audio
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredAudioLanguage(@Nullable String preferredAudioLanguage) {
       delegate.setPreferredAudioLanguage(preferredAudioLanguage);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredAudioLanguages(String... preferredAudioLanguages) {
       delegate.setPreferredAudioLanguages(preferredAudioLanguages);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredAudioRoleFlags(@C.RoleFlags int preferredAudioRoleFlags) {
       delegate.setPreferredAudioRoleFlags(preferredAudioRoleFlags);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setMaxAudioChannelCount(int maxAudioChannelCount) {
       delegate.setMaxAudioChannelCount(maxAudioChannelCount);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setMaxAudioBitrate(int maxAudioBitrate) {
       delegate.setMaxAudioBitrate(maxAudioBitrate);
@@ -339,6 +364,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     selection can be made otherwise.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setExceedAudioConstraintsIfNecessary(
         boolean exceedAudioConstraintsIfNecessary) {
       delegate.setExceedAudioConstraintsIfNecessary(exceedAudioConstraintsIfNecessary);
@@ -354,6 +380,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     containing mixed MIME types.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowAudioMixedMimeTypeAdaptiveness(
         boolean allowAudioMixedMimeTypeAdaptiveness) {
       delegate.setAllowAudioMixedMimeTypeAdaptiveness(allowAudioMixedMimeTypeAdaptiveness);
@@ -369,6 +396,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     containing mixed sample rates.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowAudioMixedSampleRateAdaptiveness(
         boolean allowAudioMixedSampleRateAdaptiveness) {
       delegate.setAllowAudioMixedSampleRateAdaptiveness(allowAudioMixedSampleRateAdaptiveness);
@@ -384,6 +412,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     containing mixed channel counts.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowAudioMixedChannelCountAdaptiveness(
         boolean allowAudioMixedChannelCountAdaptiveness) {
       delegate.setAllowAudioMixedChannelCountAdaptiveness(allowAudioMixedChannelCountAdaptiveness);
@@ -399,6 +428,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     with mixed levels of decoder and hardware acceleration support.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowAudioMixedDecoderSupportAdaptiveness(
         boolean allowAudioMixedDecoderSupportAdaptiveness) {
       delegate.setAllowAudioMixedDecoderSupportAdaptiveness(
@@ -406,12 +436,14 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredAudioMimeType(@Nullable String mimeType) {
       delegate.setPreferredAudioMimeType(mimeType);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredAudioMimeTypes(String... mimeTypes) {
       delegate.setPreferredAudioMimeTypes(mimeTypes);
@@ -420,6 +452,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
     // Text
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredTextLanguageAndRoleFlagsToCaptioningManagerSettings(
         Context context) {
@@ -427,24 +460,28 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredTextLanguage(@Nullable String preferredTextLanguage) {
       delegate.setPreferredTextLanguage(preferredTextLanguage);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredTextLanguages(String... preferredTextLanguages) {
       delegate.setPreferredTextLanguages(preferredTextLanguages);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setPreferredTextRoleFlags(@C.RoleFlags int preferredTextRoleFlags) {
       delegate.setPreferredTextRoleFlags(preferredTextRoleFlags);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setIgnoredTextSelectionFlags(
         @C.SelectionFlags int ignoredTextSelectionFlags) {
@@ -452,6 +489,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setSelectUndeterminedTextLanguage(
         boolean selectUndeterminedTextLanguage) {
@@ -462,6 +500,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
     /**
      * @deprecated Use {@link #setIgnoredTextSelectionFlags}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public ParametersBuilder setDisabledTextTrackSelectionFlags(
         @C.SelectionFlags int disabledTextTrackSelectionFlags) {
@@ -471,42 +510,49 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
     // General
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setForceLowestBitrate(boolean forceLowestBitrate) {
       delegate.setForceLowestBitrate(forceLowestBitrate);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setForceHighestSupportedBitrate(boolean forceHighestSupportedBitrate) {
       delegate.setForceHighestSupportedBitrate(forceHighestSupportedBitrate);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder addOverride(TrackSelectionOverride override) {
       delegate.addOverride(override);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder clearOverride(TrackGroup trackGroup) {
       delegate.clearOverride(trackGroup);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setOverrideForType(TrackSelectionOverride override) {
       delegate.setOverrideForType(override);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder clearOverridesOfType(@C.TrackType int trackType) {
       delegate.clearOverridesOfType(trackType);
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder clearOverrides() {
       delegate.clearOverrides();
@@ -516,6 +562,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
     /**
      * @deprecated Use {@link #setTrackTypeDisabled(int, boolean)}.
      */
+    @CanIgnoreReturnValue
     @Override
     @Deprecated
     @SuppressWarnings("deprecation")
@@ -524,6 +571,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public ParametersBuilder setTrackTypeDisabled(@C.TrackType int trackType, boolean disabled) {
       delegate.setTrackTypeDisabled(trackType, disabled);
@@ -542,6 +590,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      *     selection can be made otherwise.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setExceedRendererCapabilitiesIfNecessary(
         boolean exceedRendererCapabilitiesIfNecessary) {
       delegate.setExceedRendererCapabilitiesIfNecessary(exceedRendererCapabilitiesIfNecessary);
@@ -562,6 +611,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @param tunnelingEnabled Whether to enable tunneling if possible.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setTunnelingEnabled(boolean tunnelingEnabled) {
       delegate.setTunnelingEnabled(tunnelingEnabled);
       return this;
@@ -573,6 +623,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @param allowMultipleAdaptiveSelections Whether multiple adaptive selections are allowed.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setAllowMultipleAdaptiveSelections(
         boolean allowMultipleAdaptiveSelections) {
       delegate.setAllowMultipleAdaptiveSelections(allowMultipleAdaptiveSelections);
@@ -589,6 +640,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @param disabled Whether the renderer is disabled.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public ParametersBuilder setRendererDisabled(int rendererIndex, boolean disabled) {
       delegate.setRendererDisabled(rendererIndex, disabled);
       return this;
@@ -618,6 +670,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @return This builder.
      * @deprecated Use {@link TrackSelectionParameters.Builder#addOverride(TrackSelectionOverride)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public ParametersBuilder setSelectionOverride(
         int rendererIndex, TrackGroupArray groups, @Nullable SelectionOverride override) {
@@ -633,6 +686,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @return This builder.
      * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverride(TrackGroup)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public ParametersBuilder clearSelectionOverride(int rendererIndex, TrackGroupArray groups) {
       delegate.clearSelectionOverride(rendererIndex, groups);
@@ -646,6 +700,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @return This builder.
      * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverridesOfType(int)}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public ParametersBuilder clearSelectionOverrides(int rendererIndex) {
       delegate.clearSelectionOverrides(rendererIndex);
@@ -658,6 +713,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
      * @return This builder.
      * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverrides()}.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public ParametersBuilder clearSelectionOverrides() {
       delegate.clearSelectionOverrides();
@@ -832,6 +888,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
                     Parameters.keyForField(Parameters.FIELD_RENDERER_DISABLED_INDICES)));
       }
 
+      @CanIgnoreReturnValue
       @Override
       protected Builder set(TrackSelectionParameters parameters) {
         super.set(parameters);
@@ -840,48 +897,56 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
       // Video
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxVideoSizeSd() {
         super.setMaxVideoSizeSd();
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder clearVideoSizeConstraints() {
         super.clearVideoSizeConstraints();
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxVideoSize(int maxVideoWidth, int maxVideoHeight) {
         super.setMaxVideoSize(maxVideoWidth, maxVideoHeight);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxVideoFrameRate(int maxVideoFrameRate) {
         super.setMaxVideoFrameRate(maxVideoFrameRate);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxVideoBitrate(int maxVideoBitrate) {
         super.setMaxVideoBitrate(maxVideoBitrate);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMinVideoSize(int minVideoWidth, int minVideoHeight) {
         super.setMinVideoSize(minVideoWidth, minVideoHeight);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMinVideoFrameRate(int minVideoFrameRate) {
         super.setMinVideoFrameRate(minVideoFrameRate);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMinVideoBitrate(int minVideoBitrate) {
         super.setMinVideoBitrate(minVideoBitrate);
@@ -896,6 +961,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     selection can be made otherwise.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setExceedVideoConstraintsIfNecessary(
           boolean exceedVideoConstraintsIfNecessary) {
         this.exceedVideoConstraintsIfNecessary = exceedVideoConstraintsIfNecessary;
@@ -913,6 +979,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     containing mixed MIME types.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowVideoMixedMimeTypeAdaptiveness(
           boolean allowVideoMixedMimeTypeAdaptiveness) {
         this.allowVideoMixedMimeTypeAdaptiveness = allowVideoMixedMimeTypeAdaptiveness;
@@ -927,6 +994,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     adaptation may not be completely seamless.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowVideoNonSeamlessAdaptiveness(
           boolean allowVideoNonSeamlessAdaptiveness) {
         this.allowVideoNonSeamlessAdaptiveness = allowVideoNonSeamlessAdaptiveness;
@@ -942,12 +1010,14 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     with mixed levels of decoder and hardware acceleration support.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowVideoMixedDecoderSupportAdaptiveness(
           boolean allowVideoMixedDecoderSupportAdaptiveness) {
         this.allowVideoMixedDecoderSupportAdaptiveness = allowVideoMixedDecoderSupportAdaptiveness;
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setViewportSizeToPhysicalDisplaySize(
           Context context, boolean viewportOrientationMayChange) {
@@ -955,12 +1025,14 @@ public class DefaultTrackSelector extends MappingTrackSelector {
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder clearViewportSizeConstraints() {
         super.clearViewportSizeConstraints();
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setViewportSize(
           int viewportWidth, int viewportHeight, boolean viewportOrientationMayChange) {
@@ -968,18 +1040,21 @@ public class DefaultTrackSelector extends MappingTrackSelector {
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredVideoMimeType(@Nullable String mimeType) {
         super.setPreferredVideoMimeType(mimeType);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredVideoMimeTypes(String... mimeTypes) {
         super.setPreferredVideoMimeTypes(mimeTypes);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredVideoRoleFlags(@RoleFlags int preferredVideoRoleFlags) {
         super.setPreferredVideoRoleFlags(preferredVideoRoleFlags);
@@ -988,30 +1063,35 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
       // Audio
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredAudioLanguage(@Nullable String preferredAudioLanguage) {
         super.setPreferredAudioLanguage(preferredAudioLanguage);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredAudioLanguages(String... preferredAudioLanguages) {
         super.setPreferredAudioLanguages(preferredAudioLanguages);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredAudioRoleFlags(@C.RoleFlags int preferredAudioRoleFlags) {
         super.setPreferredAudioRoleFlags(preferredAudioRoleFlags);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxAudioChannelCount(int maxAudioChannelCount) {
         super.setMaxAudioChannelCount(maxAudioChannelCount);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setMaxAudioBitrate(int maxAudioBitrate) {
         super.setMaxAudioBitrate(maxAudioBitrate);
@@ -1026,6 +1106,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     selection can be made otherwise.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setExceedAudioConstraintsIfNecessary(
           boolean exceedAudioConstraintsIfNecessary) {
         this.exceedAudioConstraintsIfNecessary = exceedAudioConstraintsIfNecessary;
@@ -1041,6 +1122,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     containing mixed MIME types.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowAudioMixedMimeTypeAdaptiveness(
           boolean allowAudioMixedMimeTypeAdaptiveness) {
         this.allowAudioMixedMimeTypeAdaptiveness = allowAudioMixedMimeTypeAdaptiveness;
@@ -1056,6 +1138,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     containing mixed sample rates.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowAudioMixedSampleRateAdaptiveness(
           boolean allowAudioMixedSampleRateAdaptiveness) {
         this.allowAudioMixedSampleRateAdaptiveness = allowAudioMixedSampleRateAdaptiveness;
@@ -1071,6 +1154,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     containing mixed channel counts.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowAudioMixedChannelCountAdaptiveness(
           boolean allowAudioMixedChannelCountAdaptiveness) {
         this.allowAudioMixedChannelCountAdaptiveness = allowAudioMixedChannelCountAdaptiveness;
@@ -1086,18 +1170,21 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     with mixed levels of decoder and hardware acceleration support.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowAudioMixedDecoderSupportAdaptiveness(
           boolean allowAudioMixedDecoderSupportAdaptiveness) {
         this.allowAudioMixedDecoderSupportAdaptiveness = allowAudioMixedDecoderSupportAdaptiveness;
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredAudioMimeType(@Nullable String mimeType) {
         super.setPreferredAudioMimeType(mimeType);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredAudioMimeTypes(String... mimeTypes) {
         super.setPreferredAudioMimeTypes(mimeTypes);
@@ -1129,6 +1216,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * DefaultTrackSelector#DefaultTrackSelector(TrackSelectionParameters,
        * ExoTrackSelection.Factory)} constructor.
        */
+      @CanIgnoreReturnValue
       public Builder setConstrainAudioChannelCountToDeviceCapabilities(boolean enabled) {
         constrainAudioChannelCountToDeviceCapabilities = enabled;
         return this;
@@ -1136,6 +1224,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
       // Text
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredTextLanguageAndRoleFlagsToCaptioningManagerSettings(
           Context context) {
@@ -1143,30 +1232,35 @@ public class DefaultTrackSelector extends MappingTrackSelector {
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredTextLanguage(@Nullable String preferredTextLanguage) {
         super.setPreferredTextLanguage(preferredTextLanguage);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredTextLanguages(String... preferredTextLanguages) {
         super.setPreferredTextLanguages(preferredTextLanguages);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setPreferredTextRoleFlags(@C.RoleFlags int preferredTextRoleFlags) {
         super.setPreferredTextRoleFlags(preferredTextRoleFlags);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setIgnoredTextSelectionFlags(@C.SelectionFlags int ignoredTextSelectionFlags) {
         super.setIgnoredTextSelectionFlags(ignoredTextSelectionFlags);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setSelectUndeterminedTextLanguage(boolean selectUndeterminedTextLanguage) {
         super.setSelectUndeterminedTextLanguage(selectUndeterminedTextLanguage);
@@ -1176,6 +1270,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       /**
        * @deprecated Use {@link #setIgnoredTextSelectionFlags}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       public Builder setDisabledTextTrackSelectionFlags(
           @C.SelectionFlags int disabledTextTrackSelectionFlags) {
@@ -1184,42 +1279,49 @@ public class DefaultTrackSelector extends MappingTrackSelector {
 
       // General
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setForceLowestBitrate(boolean forceLowestBitrate) {
         super.setForceLowestBitrate(forceLowestBitrate);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setForceHighestSupportedBitrate(boolean forceHighestSupportedBitrate) {
         super.setForceHighestSupportedBitrate(forceHighestSupportedBitrate);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder addOverride(TrackSelectionOverride override) {
         super.addOverride(override);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder clearOverride(TrackGroup trackGroup) {
         super.clearOverride(trackGroup);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setOverrideForType(TrackSelectionOverride override) {
         super.setOverrideForType(override);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder clearOverridesOfType(@C.TrackType int trackType) {
         super.clearOverridesOfType(trackType);
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder clearOverrides() {
         super.clearOverrides();
@@ -1229,6 +1331,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
       /**
        * @deprecated Use {@link #setTrackTypeDisabled(int, boolean)}.
        */
+      @CanIgnoreReturnValue
       @Override
       @Deprecated
       @SuppressWarnings("deprecation")
@@ -1237,6 +1340,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
         return this;
       }
 
+      @CanIgnoreReturnValue
       @Override
       public Builder setTrackTypeDisabled(@C.TrackType int trackType, boolean disabled) {
         super.setTrackTypeDisabled(trackType, disabled);
@@ -1255,6 +1359,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        *     no selection can be made otherwise.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setExceedRendererCapabilitiesIfNecessary(
           boolean exceedRendererCapabilitiesIfNecessary) {
         this.exceedRendererCapabilitiesIfNecessary = exceedRendererCapabilitiesIfNecessary;
@@ -1275,6 +1380,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @param tunnelingEnabled Whether to enable tunneling if possible.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setTunnelingEnabled(boolean tunnelingEnabled) {
         this.tunnelingEnabled = tunnelingEnabled;
         return this;
@@ -1286,6 +1392,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @param allowMultipleAdaptiveSelections Whether multiple adaptive selections are allowed.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setAllowMultipleAdaptiveSelections(boolean allowMultipleAdaptiveSelections) {
         this.allowMultipleAdaptiveSelections = allowMultipleAdaptiveSelections;
         return this;
@@ -1301,6 +1408,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @param disabled Whether the renderer is disabled.
        * @return This builder.
        */
+      @CanIgnoreReturnValue
       public Builder setRendererDisabled(int rendererIndex, boolean disabled) {
         if (rendererDisabledFlags.get(rendererIndex) == disabled) {
           // The disabled flag is unchanged.
@@ -1340,6 +1448,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @deprecated Use {@link
        *     TrackSelectionParameters.Builder#addOverride(TrackSelectionOverride)}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       public Builder setSelectionOverride(
           int rendererIndex, TrackGroupArray groups, @Nullable SelectionOverride override) {
@@ -1365,6 +1474,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @return This builder.
        * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverride(TrackGroup)}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       public Builder clearSelectionOverride(int rendererIndex, TrackGroupArray groups) {
         Map<TrackGroupArray, @NullableType SelectionOverride> overrides =
@@ -1387,6 +1497,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @return This builder.
        * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverridesOfType(int)}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       public Builder clearSelectionOverrides(int rendererIndex) {
         Map<TrackGroupArray, @NullableType SelectionOverride> overrides =
@@ -1405,6 +1516,7 @@ public class DefaultTrackSelector extends MappingTrackSelector {
        * @return This builder.
        * @deprecated Use {@link TrackSelectionParameters.Builder#clearOverrides()}.
        */
+      @CanIgnoreReturnValue
       @Deprecated
       public Builder clearSelectionOverrides() {
         if (selectionOverrides.size() == 0) {

library/core/src/main/java/com/google/android/exoplayer2/upstream/DefaultBandwidthMeter.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Ascii;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -136,6 +137,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      * @param slidingWindowMaxWeight The maximum weight for the sliding window.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSlidingWindowMaxWeight(int slidingWindowMaxWeight) {
       this.slidingWindowMaxWeight = slidingWindowMaxWeight;
       return this;
@@ -148,6 +150,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      * @param initialBitrateEstimate The initial bitrate estimate in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setInitialBitrateEstimate(long initialBitrateEstimate) {
       for (Integer networkType : initialBitrateEstimates.keySet()) {
         setInitialBitrateEstimate(networkType, initialBitrateEstimate);
@@ -163,6 +166,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      * @param initialBitrateEstimate The initial bitrate estimate in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setInitialBitrateEstimate(
         @C.NetworkType int networkType, long initialBitrateEstimate) {
       initialBitrateEstimates.put(networkType, initialBitrateEstimate);
@@ -177,6 +181,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      *     estimates should be used.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setInitialBitrateEstimate(String countryCode) {
       initialBitrateEstimates =
           getInitialBitrateEstimatesForCountry(Ascii.toUpperCase(countryCode));
@@ -190,6 +195,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      * @param clock The clock used to estimate bandwidth from data transfers.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setClock(Clock clock) {
       this.clock = clock;
       return this;
@@ -201,6 +207,7 @@ public final class DefaultBandwidthMeter implements BandwidthMeter, TransferList
      * @param resetOnNetworkTypeChange Whether to reset if the network type changes.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setResetOnNetworkTypeChange(boolean resetOnNetworkTypeChange) {
       this.resetOnNetworkTypeChange = resetOnNetworkTypeChange;
       return this;

library/core/src/test/java/com/google/android/exoplayer2/ExoPlayerTest.java

@@ -155,6 +155,7 @@ import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
 import com.google.common.collect.Range;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -12183,6 +12184,7 @@ public final class ExoPlayerTest {
     }
 
     /** Call {@link Renderer.WakeupListener#onSleep()} on the next {@link #render(long, long)} */
+    @CanIgnoreReturnValue
     public FakeSleepRenderer sleepOnNextRender() {
       sleepOnNextRender.set(true);
       return this;

library/dash/build.gradle

@@ -25,6 +25,7 @@ android {
 
 dependencies {
     implementation project(modulePrefix + 'library-core')
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

library/dash/src/main/java/com/google/android/exoplayer2/source/dash/DashMediaSource.java

@@ -76,6 +76,7 @@ import com.google.android.exoplayer2.util.SntpClient;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Charsets;
 import com.google.common.math.LongMath;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
@@ -156,6 +157,7 @@ public final class DashMediaSource extends BaseMediaSource {
       compositeSequenceableLoaderFactory = new DefaultCompositeSequenceableLoaderFactory();
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setDrmSessionManagerProvider(
         DrmSessionManagerProvider drmSessionManagerProvider) {
@@ -168,6 +170,7 @@ public final class DashMediaSource extends BaseMediaSource {
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy =
@@ -188,6 +191,7 @@ public final class DashMediaSource extends BaseMediaSource {
      * @param fallbackTargetLiveOffsetMs The fallback live target offset in milliseconds.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setFallbackTargetLiveOffsetMs(long fallbackTargetLiveOffsetMs) {
       this.fallbackTargetLiveOffsetMs = fallbackTargetLiveOffsetMs;
       return this;
@@ -199,6 +203,7 @@ public final class DashMediaSource extends BaseMediaSource {
      * @param manifestParser A parser for loaded manifest data.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setManifestParser(
         @Nullable ParsingLoadable.Parser<? extends DashManifest> manifestParser) {
       this.manifestParser = manifestParser;
@@ -215,6 +220,7 @@ public final class DashMediaSource extends BaseMediaSource {
      *     audio etc...).
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setCompositeSequenceableLoaderFactory(
         CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory) {
       this.compositeSequenceableLoaderFactory =

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/DataSpec.java

@@ -23,6 +23,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.ExoPlayerLibraryInfo;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -87,6 +88,7 @@ public final class DataSpec {
      * @param uriString The {@link DataSpec#uri}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUri(String uriString) {
       this.uri = Uri.parse(uriString);
       return this;
@@ -98,6 +100,7 @@ public final class DataSpec {
      * @param uri The {@link DataSpec#uri}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUri(Uri uri) {
       this.uri = uri;
       return this;
@@ -109,6 +112,7 @@ public final class DataSpec {
      * @param uriPositionOffset The {@link DataSpec#uriPositionOffset}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUriPositionOffset(long uriPositionOffset) {
       this.uriPositionOffset = uriPositionOffset;
       return this;
@@ -120,6 +124,7 @@ public final class DataSpec {
      * @param httpMethod The {@link DataSpec#httpMethod}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setHttpMethod(@HttpMethod int httpMethod) {
       this.httpMethod = httpMethod;
       return this;
@@ -131,6 +136,7 @@ public final class DataSpec {
      * @param httpBody The {@link DataSpec#httpBody}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setHttpBody(@Nullable byte[] httpBody) {
       this.httpBody = httpBody;
       return this;
@@ -146,6 +152,7 @@ public final class DataSpec {
      * @param httpRequestHeaders The {@link DataSpec#httpRequestHeaders}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setHttpRequestHeaders(Map<String, String> httpRequestHeaders) {
       this.httpRequestHeaders = httpRequestHeaders;
       return this;
@@ -157,6 +164,7 @@ public final class DataSpec {
      * @param position The {@link DataSpec#position}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPosition(long position) {
       this.position = position;
       return this;
@@ -168,6 +176,7 @@ public final class DataSpec {
      * @param length The {@link DataSpec#length}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLength(long length) {
       this.length = length;
       return this;
@@ -179,6 +188,7 @@ public final class DataSpec {
      * @param key The {@link DataSpec#key}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setKey(@Nullable String key) {
       this.key = key;
       return this;
@@ -190,6 +200,7 @@ public final class DataSpec {
      * @param flags The {@link DataSpec#flags}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setFlags(@Flags int flags) {
       this.flags = flags;
       return this;
@@ -201,6 +212,7 @@ public final class DataSpec {
      * @param customData The {@link DataSpec#customData}.
      * @return The builder.
      */
+    @CanIgnoreReturnValue
     public Builder setCustomData(@Nullable Object customData) {
       this.customData = customData;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/DefaultDataSource.java

@@ -22,6 +22,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -98,6 +99,7 @@ public final class DefaultDataSource implements DataSource {
      * @param transferListener The listener that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setTransferListener(@Nullable TransferListener transferListener) {
       this.transferListener = transferListener;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/DefaultHttpDataSource.java

@@ -33,6 +33,7 @@ import com.google.common.collect.ForwardingMap;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Sets;
 import com.google.common.net.HttpHeaders;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InterruptedIOException;
@@ -81,6 +82,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
       readTimeoutMs = DEFAULT_READ_TIMEOUT_MILLIS;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public final Factory setDefaultRequestProperties(Map<String, String> defaultRequestProperties) {
       this.defaultRequestProperties.clearAndSet(defaultRequestProperties);
@@ -97,6 +99,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      *     agent of the underlying platform.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUserAgent(@Nullable String userAgent) {
       this.userAgent = userAgent;
       return this;
@@ -110,6 +113,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      * @param connectTimeoutMs The connect timeout, in milliseconds, that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setConnectTimeoutMs(int connectTimeoutMs) {
       this.connectTimeoutMs = connectTimeoutMs;
       return this;
@@ -123,6 +127,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      * @param readTimeoutMs The connect timeout, in milliseconds, that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setReadTimeoutMs(int readTimeoutMs) {
       this.readTimeoutMs = readTimeoutMs;
       return this;
@@ -136,6 +141,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      * @param allowCrossProtocolRedirects Whether to allow cross protocol redirects.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setAllowCrossProtocolRedirects(boolean allowCrossProtocolRedirects) {
       this.allowCrossProtocolRedirects = allowCrossProtocolRedirects;
       return this;
@@ -152,6 +158,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      *     predicate that was previously set.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setContentTypePredicate(@Nullable Predicate<String> contentTypePredicate) {
       this.contentTypePredicate = contentTypePredicate;
       return this;
@@ -167,6 +174,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      * @param transferListener The listener that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setTransferListener(@Nullable TransferListener transferListener) {
       this.transferListener = transferListener;
       return this;
@@ -176,6 +184,7 @@ public class DefaultHttpDataSource extends BaseDataSource implements HttpDataSou
      * Sets whether we should keep the POST method and body when we have HTTP 302 redirects for a
      * POST request.
      */
+    @CanIgnoreReturnValue
     public Factory setKeepPostFor302Redirects(boolean keepPostFor302Redirects) {
       this.keepPostFor302Redirects = keepPostFor302Redirects;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/FileDataSource.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.PlaybackException;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.io.RandomAccessFile;
@@ -80,6 +81,7 @@ public final class FileDataSource extends BaseDataSource {
      * @param listener The {@link TransferListener}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setListener(@Nullable TransferListener listener) {
       this.listener = listener;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/HttpDataSource.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.PlaybackException;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Ascii;
 import com.google.common.base.Predicate;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.lang.annotation.Documented;
@@ -152,6 +153,7 @@ public interface HttpDataSource extends DataSource {
       return createDataSourceInternal(defaultRequestProperties);
     }
 
+    @CanIgnoreReturnValue
     @Override
     public final Factory setDefaultRequestProperties(Map<String, String> defaultRequestProperties) {
       this.defaultRequestProperties.clearAndSet(defaultRequestProperties);

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSink.java

@@ -27,6 +27,7 @@ import com.google.android.exoplayer2.upstream.cache.Cache.CacheException;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.File;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -63,6 +64,7 @@ public final class CacheDataSink implements DataSink {
      * @param cache The cache to which data will be written.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCache(Cache cache) {
       this.cache = cache;
       return this;
@@ -81,6 +83,7 @@ public final class CacheDataSink implements DataSink {
      *     fragmentation.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setFragmentSize(long fragmentSize) {
       this.fragmentSize = fragmentSize;
       return this;
@@ -95,6 +98,7 @@ public final class CacheDataSink implements DataSink {
      * @param bufferSize The buffer size in bytes.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setBufferSize(int bufferSize) {
       this.bufferSize = bufferSize;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheDataSource.java

@@ -41,6 +41,7 @@ import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.upstream.cache.Cache.CacheException;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.PriorityTaskManager;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.InterruptedIOException;
 import java.lang.annotation.Documented;
@@ -86,6 +87,7 @@ public final class CacheDataSource implements DataSource {
      * @param cache The cache that will be used.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCache(Cache cache) {
       this.cache = cache;
       return this;
@@ -109,6 +111,7 @@ public final class CacheDataSource implements DataSource {
      * @param cacheReadDataSourceFactory The {@link DataSource.Factory} for reading from the cache.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCacheReadDataSourceFactory(DataSource.Factory cacheReadDataSourceFactory) {
       this.cacheReadDataSourceFactory = cacheReadDataSourceFactory;
       return this;
@@ -124,6 +127,7 @@ public final class CacheDataSource implements DataSource {
      *     DataSinks} for writing data to the cache, or {@code null} to disable writing.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCacheWriteDataSinkFactory(
         @Nullable DataSink.Factory cacheWriteDataSinkFactory) {
       this.cacheWriteDataSinkFactory = cacheWriteDataSinkFactory;
@@ -139,6 +143,7 @@ public final class CacheDataSource implements DataSource {
      * @param cacheKeyFactory The {@link CacheKeyFactory}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setCacheKeyFactory(CacheKeyFactory cacheKeyFactory) {
       this.cacheKeyFactory = cacheKeyFactory;
       return this;
@@ -160,6 +165,7 @@ public final class CacheDataSource implements DataSource {
      *     cache, or {@code null} to cause failure in the case of a cache miss.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUpstreamDataSourceFactory(
         @Nullable DataSource.Factory upstreamDataSourceFactory) {
       this.upstreamDataSourceFactory = upstreamDataSourceFactory;
@@ -184,6 +190,7 @@ public final class CacheDataSource implements DataSource {
      * @param upstreamPriorityTaskManager The upstream {@link PriorityTaskManager}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUpstreamPriorityTaskManager(
         @Nullable PriorityTaskManager upstreamPriorityTaskManager) {
       this.upstreamPriorityTaskManager = upstreamPriorityTaskManager;
@@ -208,6 +215,7 @@ public final class CacheDataSource implements DataSource {
      * @param upstreamPriority The priority to use when requesting data from upstream.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setUpstreamPriority(int upstreamPriority) {
       this.upstreamPriority = upstreamPriority;
       return this;
@@ -221,6 +229,7 @@ public final class CacheDataSource implements DataSource {
      * @param flags The {@link CacheDataSource.Flags}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setFlags(@CacheDataSource.Flags int flags) {
       this.flags = flags;
       return this;
@@ -234,6 +243,7 @@ public final class CacheDataSource implements DataSource {
      * @param eventListener The {@link EventListener}.
      * @return This factory.
      */
+    @CanIgnoreReturnValue
     public Factory setEventListener(@Nullable EventListener eventListener) {
       this.eventListener = eventListener;
       return this;

library/datasource/src/main/java/com/google/android/exoplayer2/upstream/cache/ContentMetadataMutations.java

@@ -19,6 +19,7 @@ import android.net.Uri;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -79,6 +80,7 @@ public class ContentMetadataMutations {
    * @param value The value to be set.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ContentMetadataMutations set(String name, String value) {
     return checkAndSet(name, value);
   }
@@ -90,6 +92,7 @@ public class ContentMetadataMutations {
    * @param value The value to be set.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ContentMetadataMutations set(String name, long value) {
     return checkAndSet(name, value);
   }
@@ -101,6 +104,7 @@ public class ContentMetadataMutations {
    * @param value The value to be set.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ContentMetadataMutations set(String name, byte[] value) {
     return checkAndSet(name, Arrays.copyOf(value, value.length));
   }
@@ -111,6 +115,7 @@ public class ContentMetadataMutations {
    * @param name The name of the metadata value.
    * @return This instance, for convenience.
    */
+  @CanIgnoreReturnValue
   public ContentMetadataMutations remove(String name) {
     removedValues.add(name);
     editedValues.remove(name);
@@ -135,6 +140,7 @@ public class ContentMetadataMutations {
     return Collections.unmodifiableMap(hashMap);
   }
 
+  @CanIgnoreReturnValue
   private ContentMetadataMutations checkAndSet(String name, Object value) {
     editedValues.put(Assertions.checkNotNull(name), Assertions.checkNotNull(value));
     removedValues.remove(name);

library/extractor/build.gradle

@@ -28,6 +28,7 @@ dependencies {
     implementation project(modulePrefix + 'library-common')
     // TODO(b/203752187): Remove this dependency.
     implementation project(modulePrefix + 'library-decoder')
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/DefaultExtractorsFactory.java

@@ -43,6 +43,7 @@ import com.google.android.exoplayer2.extractor.ts.TsPayloadReader;
 import com.google.android.exoplayer2.extractor.wav.WavExtractor;
 import com.google.android.exoplayer2.util.FileTypes;
 import com.google.android.exoplayer2.util.TimestampAdjuster;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
@@ -143,6 +144,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    *     assumption should be enabled for all extractors that support it.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setConstantBitrateSeekingEnabled(
       boolean constantBitrateSeekingEnabled) {
     this.constantBitrateSeekingEnabled = constantBitrateSeekingEnabled;
@@ -167,6 +169,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    *     duration is unknown.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setConstantBitrateSeekingAlwaysEnabled(
       boolean constantBitrateSeekingAlwaysEnabled) {
     this.constantBitrateSeekingAlwaysEnabled = constantBitrateSeekingAlwaysEnabled;
@@ -180,6 +183,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setAdtsExtractorFlags(
       @AdtsExtractor.Flags int flags) {
     this.adtsFlags = flags;
@@ -193,6 +197,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setAmrExtractorFlags(@AmrExtractor.Flags int flags) {
     this.amrFlags = flags;
     return this;
@@ -207,6 +212,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setFlacExtractorFlags(
       @FlacExtractor.Flags int flags) {
     this.flacFlags = flags;
@@ -220,6 +226,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setMatroskaExtractorFlags(
       @MatroskaExtractor.Flags int flags) {
     this.matroskaFlags = flags;
@@ -233,6 +240,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setMp4ExtractorFlags(@Mp4Extractor.Flags int flags) {
     this.mp4Flags = flags;
     return this;
@@ -245,6 +253,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setFragmentedMp4ExtractorFlags(
       @FragmentedMp4Extractor.Flags int flags) {
     this.fragmentedMp4Flags = flags;
@@ -258,6 +267,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setMp3ExtractorFlags(@Mp3Extractor.Flags int flags) {
     mp3Flags = flags;
     return this;
@@ -270,6 +280,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param mode The mode to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setTsExtractorMode(@TsExtractor.Mode int mode) {
     tsMode = mode;
     return this;
@@ -283,6 +294,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param flags The flags to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setTsExtractorFlags(
       @DefaultTsPayloadReaderFactory.Flags int flags) {
     tsFlags = flags;
@@ -297,6 +309,7 @@ public final class DefaultExtractorsFactory implements ExtractorsFactory {
    * @param timestampSearchBytes The number of search bytes to use.
    * @return The factory, for convenience.
    */
+  @CanIgnoreReturnValue
   public synchronized DefaultExtractorsFactory setTsExtractorTimestampSearchBytes(
       int timestampSearchBytes) {
     tsTimestampSearchBytes = timestampSearchBytes;

library/extractor/src/main/java/com/google/android/exoplayer2/text/ttml/TtmlStyle.java

@@ -22,6 +22,7 @@ import android.text.Layout;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.text.span.TextAnnotation;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -125,6 +126,7 @@ import java.lang.annotation.Target;
     return linethrough == ON;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setLinethrough(boolean linethrough) {
     this.linethrough = linethrough ? ON : OFF;
     return this;
@@ -134,16 +136,19 @@ import java.lang.annotation.Target;
     return underline == ON;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setUnderline(boolean underline) {
     this.underline = underline ? ON : OFF;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setBold(boolean bold) {
     this.bold = bold ? ON : OFF;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setItalic(boolean italic) {
     this.italic = italic ? ON : OFF;
     return this;
@@ -154,6 +159,7 @@ import java.lang.annotation.Target;
     return fontFamily;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setFontFamily(@Nullable String fontFamily) {
     this.fontFamily = fontFamily;
     return this;
@@ -166,6 +172,7 @@ import java.lang.annotation.Target;
     return fontColor;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setFontColor(int fontColor) {
     this.fontColor = fontColor;
     hasFontColor = true;
@@ -183,6 +190,7 @@ import java.lang.annotation.Target;
     return backgroundColor;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setBackgroundColor(int backgroundColor) {
     this.backgroundColor = backgroundColor;
     hasBackgroundColor = true;
@@ -193,6 +201,7 @@ import java.lang.annotation.Target;
     return hasBackgroundColor;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setShearPercentage(float shearPercentage) {
     this.shearPercentage = shearPercentage;
     return this;
@@ -208,6 +217,7 @@ import java.lang.annotation.Target;
    *
    * @param ancestor the referential style to inherit from
    */
+  @CanIgnoreReturnValue
   public TtmlStyle chain(@Nullable TtmlStyle ancestor) {
     return inherit(ancestor, true);
   }
@@ -219,10 +229,12 @@ import java.lang.annotation.Target;
    *
    * @param ancestor the ancestor style to inherit from
    */
+  @CanIgnoreReturnValue
   public TtmlStyle inherit(@Nullable TtmlStyle ancestor) {
     return inherit(ancestor, false);
   }
 
+  @CanIgnoreReturnValue
   private TtmlStyle inherit(@Nullable TtmlStyle ancestor, boolean chaining) {
     if (ancestor != null) {
       if (!hasFontColor && ancestor.hasFontColor) {
@@ -276,6 +288,7 @@ import java.lang.annotation.Target;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setId(@Nullable String id) {
     this.id = id;
     return this;
@@ -286,6 +299,7 @@ import java.lang.annotation.Target;
     return id;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setRubyType(@RubyType int rubyType) {
     this.rubyType = rubyType;
     return this;
@@ -295,6 +309,7 @@ import java.lang.annotation.Target;
     return rubyType;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setRubyPosition(@TextAnnotation.Position int position) {
     this.rubyPosition = position;
     return this;
@@ -309,6 +324,7 @@ import java.lang.annotation.Target;
     return textAlign;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setTextAlign(@Nullable Layout.Alignment textAlign) {
     this.textAlign = textAlign;
     return this;
@@ -319,6 +335,7 @@ import java.lang.annotation.Target;
     return multiRowAlign;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setMultiRowAlign(@Nullable Layout.Alignment multiRowAlign) {
     this.multiRowAlign = multiRowAlign;
     return this;
@@ -329,6 +346,7 @@ import java.lang.annotation.Target;
     return textCombine == ON;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setTextCombine(boolean combine) {
     this.textCombine = combine ? ON : OFF;
     return this;
@@ -339,16 +357,19 @@ import java.lang.annotation.Target;
     return textEmphasis;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setTextEmphasis(@Nullable TextEmphasis textEmphasis) {
     this.textEmphasis = textEmphasis;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setFontSize(float fontSize) {
     this.fontSize = fontSize;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public TtmlStyle setFontSizeUnit(int fontSizeUnit) {
     this.fontSizeUnit = fontSizeUnit;
     return this;

library/extractor/src/main/java/com/google/android/exoplayer2/text/webvtt/WebvttCssStyle.java

@@ -24,6 +24,7 @@ import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.text.span.TextAnnotation;
 import com.google.common.base.Ascii;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -195,6 +196,7 @@ public final class WebvttCssStyle {
     return linethrough == ON;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setLinethrough(boolean linethrough) {
     this.linethrough = linethrough ? ON : OFF;
     return this;
@@ -204,16 +206,19 @@ public final class WebvttCssStyle {
     return underline == ON;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setUnderline(boolean underline) {
     this.underline = underline ? ON : OFF;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setBold(boolean bold) {
     this.bold = bold ? ON : OFF;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setItalic(boolean italic) {
     this.italic = italic ? ON : OFF;
     return this;
@@ -224,6 +229,7 @@ public final class WebvttCssStyle {
     return fontFamily;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setFontFamily(@Nullable String fontFamily) {
     this.fontFamily = fontFamily == null ? null : Ascii.toLowerCase(fontFamily);
     return this;
@@ -236,6 +242,7 @@ public final class WebvttCssStyle {
     return fontColor;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setFontColor(int color) {
     this.fontColor = color;
     hasFontColor = true;
@@ -253,6 +260,7 @@ public final class WebvttCssStyle {
     return backgroundColor;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setBackgroundColor(int backgroundColor) {
     this.backgroundColor = backgroundColor;
     hasBackgroundColor = true;
@@ -263,11 +271,13 @@ public final class WebvttCssStyle {
     return hasBackgroundColor;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setFontSize(float fontSize) {
     this.fontSize = fontSize;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setFontSizeUnit(@FontSizeUnit int unit) {
     this.fontSizeUnit = unit;
     return this;
@@ -281,6 +291,7 @@ public final class WebvttCssStyle {
     return fontSize;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setRubyPosition(@TextAnnotation.Position int rubyPosition) {
     this.rubyPosition = rubyPosition;
     return this;
@@ -290,6 +301,7 @@ public final class WebvttCssStyle {
     return rubyPosition;
   }
 
+  @CanIgnoreReturnValue
   public WebvttCssStyle setCombineUpright(boolean enabled) {
     this.combineUpright = enabled;
     return this;

library/hls/build.gradle

@@ -25,6 +25,7 @@ android {
 
 dependencies {
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

library/hls/src/main/java/com/google/android/exoplayer2/source/hls/HlsMediaSource.java

@@ -55,6 +55,7 @@ import com.google.android.exoplayer2.upstream.DefaultLoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
@@ -169,12 +170,14 @@ public final class HlsMediaSource extends BaseMediaSource
      *     segments.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setExtractorFactory(@Nullable HlsExtractorFactory extractorFactory) {
       this.extractorFactory =
           extractorFactory != null ? extractorFactory : HlsExtractorFactory.DEFAULT;
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy =
@@ -192,6 +195,7 @@ public final class HlsMediaSource extends BaseMediaSource
      * @param playlistParserFactory An {@link HlsPlaylistParserFactory}.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setPlaylistParserFactory(HlsPlaylistParserFactory playlistParserFactory) {
       this.playlistParserFactory =
           checkNotNull(
@@ -208,6 +212,7 @@ public final class HlsMediaSource extends BaseMediaSource
      * @param playlistTrackerFactory A factory for {@link HlsPlaylistTracker} instances.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setPlaylistTrackerFactory(HlsPlaylistTracker.Factory playlistTrackerFactory) {
       this.playlistTrackerFactory =
           checkNotNull(
@@ -227,6 +232,7 @@ public final class HlsMediaSource extends BaseMediaSource
      *     audio etc...).
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setCompositeSequenceableLoaderFactory(
         CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory) {
       this.compositeSequenceableLoaderFactory =
@@ -246,6 +252,7 @@ public final class HlsMediaSource extends BaseMediaSource
      * @param allowChunklessPreparation Whether chunkless preparation is allowed.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setAllowChunklessPreparation(boolean allowChunklessPreparation) {
       this.allowChunklessPreparation = allowChunklessPreparation;
       return this;
@@ -270,6 +277,7 @@ public final class HlsMediaSource extends BaseMediaSource
      * @param metadataType The type of metadata to extract.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setMetadataType(@MetadataType int metadataType) {
       this.metadataType = metadataType;
       return this;
@@ -284,11 +292,13 @@ public final class HlsMediaSource extends BaseMediaSource
      * @param useSessionKeys Whether to use #EXT-X-SESSION-KEY tags.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setUseSessionKeys(boolean useSessionKeys) {
       this.useSessionKeys = useSessionKeys;
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setDrmSessionManagerProvider(
         DrmSessionManagerProvider drmSessionManagerProvider) {
@@ -309,6 +319,7 @@ public final class HlsMediaSource extends BaseMediaSource
      *     the time since the Unix epoch, in milliseconds.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     @VisibleForTesting
     /* package */ Factory setElapsedRealTimeOffsetMs(long elapsedRealTimeOffsetMs) {
       this.elapsedRealTimeOffsetMs = elapsedRealTimeOffsetMs;

library/rtsp/build.gradle

@@ -25,6 +25,7 @@ android {
 
 dependencies {
     implementation 'androidx.annotation:annotation:' + androidxAnnotationVersion
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/MediaDescription.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.ParserException;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -147,6 +148,7 @@ import java.util.HashMap;
      * @param mediaTitle The assigned media title.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaTitle(String mediaTitle) {
       this.mediaTitle = mediaTitle;
       return this;
@@ -158,6 +160,7 @@ import java.util.HashMap;
      * @param connection The connection parameter.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setConnection(String connection) {
       this.connection = connection;
       return this;
@@ -169,6 +172,7 @@ import java.util.HashMap;
      * @param bitrate The estimated bitrate measured in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setBitrate(int bitrate) {
       this.bitrate = bitrate;
       return this;
@@ -180,6 +184,7 @@ import java.util.HashMap;
      * @param key The encryption parameter.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setKey(String key) {
       this.key = key;
       return this;
@@ -194,6 +199,7 @@ import java.util.HashMap;
      * @param attributeValue The value of the attribute, or "" if the attribute bears no value.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addAttribute(String attributeName, String attributeValue) {
       attributes.put(attributeName, attributeValue);
       return this;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtpPacket.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.util.ParsableByteArray;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.math.IntMath;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.nio.ByteBuffer;
 
 /**
@@ -69,24 +70,28 @@ public final class RtpPacket {
     private byte[] payloadData = EMPTY;
 
     /** Sets the {@link RtpPacket#padding}. The default is false. */
+    @CanIgnoreReturnValue
     public Builder setPadding(boolean padding) {
       this.padding = padding;
       return this;
     }
 
     /** Sets {@link RtpPacket#marker}. The default is false. */
+    @CanIgnoreReturnValue
     public Builder setMarker(boolean marker) {
       this.marker = marker;
       return this;
     }
 
     /** Sets {@link RtpPacket#payloadType}. The default is 0. */
+    @CanIgnoreReturnValue
     public Builder setPayloadType(byte payloadType) {
       this.payloadType = payloadType;
       return this;
     }
 
     /** Sets {@link RtpPacket#sequenceNumber}. The default is 0. */
+    @CanIgnoreReturnValue
     public Builder setSequenceNumber(int sequenceNumber) {
       checkArgument(sequenceNumber >= MIN_SEQUENCE_NUMBER && sequenceNumber <= MAX_SEQUENCE_NUMBER);
       this.sequenceNumber = sequenceNumber & 0xFFFF;
@@ -94,18 +99,21 @@ public final class RtpPacket {
     }
 
     /** Sets {@link RtpPacket#timestamp}. The default is 0. */
+    @CanIgnoreReturnValue
     public Builder setTimestamp(long timestamp) {
       this.timestamp = timestamp;
       return this;
     }
 
     /** Sets {@link RtpPacket#ssrc}. The default is 0. */
+    @CanIgnoreReturnValue
     public Builder setSsrc(int ssrc) {
       this.ssrc = ssrc;
       return this;
     }
 
     /** Sets {@link RtpPacket#csrc}. The default is an empty byte array. */
+    @CanIgnoreReturnValue
     public Builder setCsrc(byte[] csrc) {
       checkNotNull(csrc);
       this.csrc = csrc;
@@ -113,6 +121,7 @@ public final class RtpPacket {
     }
 
     /** Sets {@link RtpPacket#payloadData}. The default is an empty byte array. */
+    @CanIgnoreReturnValue
     public Builder setPayloadData(byte[] payloadData) {
       checkNotNull(payloadData);
       this.payloadData = payloadData;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspHeaders.java

@@ -22,6 +22,7 @@ import com.google.common.base.Ascii;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableListMultimap;
 import com.google.common.collect.Iterables;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.List;
 import java.util.Map;
 
@@ -113,6 +114,7 @@ import java.util.Map;
      * @param headerValue The value of the header.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder add(String headerName, String headerValue) {
       namesAndValuesBuilder.put(convertToStandardHeaderName(headerName.trim()), headerValue.trim());
       return this;
@@ -125,6 +127,7 @@ import java.util.Map;
      *     <headerValue>
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addAll(List<String> headers) {
       for (int i = 0; i < headers.size(); i++) {
         String[] header = Util.splitAtFirst(headers.get(i), ":\\s?");
@@ -142,6 +145,7 @@ import java.util.Map;
      *     header values.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addAll(Map<String, String> headers) {
       for (Map.Entry<String, String> header : headers.entrySet()) {
         add(header.getKey(), header.getValue());

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/RtspMediaSource.java

@@ -38,6 +38,7 @@ import com.google.android.exoplayer2.upstream.Allocator;
 import com.google.android.exoplayer2.upstream.LoadErrorHandlingPolicy;
 import com.google.android.exoplayer2.upstream.TransferListener;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import javax.net.SocketFactory;
 
@@ -87,6 +88,7 @@ public final class RtspMediaSource extends BaseMediaSource {
      * @param forceUseRtpTcp Whether force to use TCP for streaming.
      * @return This Factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setForceUseRtpTcp(boolean forceUseRtpTcp) {
       this.forceUseRtpTcp = forceUseRtpTcp;
       return this;
@@ -98,6 +100,7 @@ public final class RtspMediaSource extends BaseMediaSource {
      * @param userAgent The user agent.
      * @return This Factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setUserAgent(String userAgent) {
       this.userAgent = userAgent;
       return this;
@@ -110,6 +113,7 @@ public final class RtspMediaSource extends BaseMediaSource {
      * @param socketFactory A socket factory.
      * @return This Factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setSocketFactory(SocketFactory socketFactory) {
       this.socketFactory = socketFactory;
       return this;
@@ -124,6 +128,7 @@ public final class RtspMediaSource extends BaseMediaSource {
      * @param debugLoggingEnabled Whether to log RTSP messages.
      * @return This Factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setDebugLoggingEnabled(boolean debugLoggingEnabled) {
       this.debugLoggingEnabled = debugLoggingEnabled;
       return this;
@@ -138,6 +143,7 @@ public final class RtspMediaSource extends BaseMediaSource {
      * @param timeoutMs The timeout measured in milliseconds.
      * @return This Factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setTimeoutMs(@IntRange(from = 1) long timeoutMs) {
       checkArgument(timeoutMs > 0);
       this.timeoutMs = timeoutMs;

library/rtsp/src/main/java/com/google/android/exoplayer2/source/rtsp/SessionDescription.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.HashMap;
 
 /**
@@ -64,6 +65,7 @@ import java.util.HashMap;
      * @param sessionName The {@link SessionDescription#sessionName}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSessionName(String sessionName) {
       this.sessionName = sessionName;
       return this;
@@ -75,6 +77,7 @@ import java.util.HashMap;
      * @param sessionInfo The {@link SessionDescription#sessionInfo}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSessionInfo(String sessionInfo) {
       this.sessionInfo = sessionInfo;
       return this;
@@ -86,6 +89,7 @@ import java.util.HashMap;
      * @param uri The {@link SessionDescription#uri}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUri(Uri uri) {
       this.uri = uri;
       return this;
@@ -99,6 +103,7 @@ import java.util.HashMap;
      * @param origin The {@link SessionDescription#origin}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setOrigin(String origin) {
       this.origin = origin;
       return this;
@@ -110,6 +115,7 @@ import java.util.HashMap;
      * @param connection The {@link SessionDescription#connection}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setConnection(String connection) {
       this.connection = connection;
       return this;
@@ -121,6 +127,7 @@ import java.util.HashMap;
      * @param bitrate The {@link SessionDescription#bitrate} in bits per second.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setBitrate(int bitrate) {
       this.bitrate = bitrate;
       return this;
@@ -134,6 +141,7 @@ import java.util.HashMap;
      * @param timing The {@link SessionDescription#timing}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setTiming(String timing) {
       this.timing = timing;
       return this;
@@ -145,6 +153,7 @@ import java.util.HashMap;
      * @param key The {@link SessionDescription#key}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setKey(String key) {
       this.key = key;
       return this;
@@ -156,6 +165,7 @@ import java.util.HashMap;
      * @param emailAddress The {@link SessionDescription#emailAddress}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEmailAddress(String emailAddress) {
       this.emailAddress = emailAddress;
       return this;
@@ -167,6 +177,7 @@ import java.util.HashMap;
      * @param phoneNumber The {@link SessionDescription#phoneNumber}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPhoneNumber(String phoneNumber) {
       this.phoneNumber = phoneNumber;
       return this;
@@ -179,6 +190,7 @@ import java.util.HashMap;
      * @param attributeValue The value of the attribute.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addAttribute(String attributeName, String attributeValue) {
       attributes.put(attributeName, attributeValue);
       return this;
@@ -190,6 +202,7 @@ import java.util.HashMap;
      * @param mediaDescription The {@link MediaDescription}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addMediaDescription(MediaDescription mediaDescription) {
       mediaDescriptionListBuilder.add(mediaDescription);
       return this;

library/smoothstreaming/build.gradle

@@ -25,6 +25,7 @@ android {
 
 dependencies {
     implementation project(modulePrefix + 'library-core')
+    compileOnly 'com.google.errorprone:error_prone_annotations:' + errorProneVersion
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     compileOnly 'org.checkerframework:checker-compat-qual:' + checkerframeworkCompatVersion
     compileOnly 'org.jetbrains.kotlin:kotlin-annotations-jvm:' + kotlinAnnotationsVersion

library/smoothstreaming/src/main/java/com/google/android/exoplayer2/source/smoothstreaming/SsMediaSource.java

@@ -63,6 +63,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -134,6 +135,7 @@ public final class SsMediaSource extends BaseMediaSource
       compositeSequenceableLoaderFactory = new DefaultCompositeSequenceableLoaderFactory();
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setLoadErrorHandlingPolicy(LoadErrorHandlingPolicy loadErrorHandlingPolicy) {
       this.loadErrorHandlingPolicy =
@@ -154,6 +156,7 @@ public final class SsMediaSource extends BaseMediaSource
      *     default start position should precede the end of the live window.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setLivePresentationDelayMs(long livePresentationDelayMs) {
       this.livePresentationDelayMs = livePresentationDelayMs;
       return this;
@@ -165,6 +168,7 @@ public final class SsMediaSource extends BaseMediaSource
      * @param manifestParser A parser for loaded manifest data.
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setManifestParser(
         @Nullable ParsingLoadable.Parser<? extends SsManifest> manifestParser) {
       this.manifestParser = manifestParser;
@@ -180,6 +184,7 @@ public final class SsMediaSource extends BaseMediaSource
      *     audio etc.).
      * @return This factory, for convenience.
      */
+    @CanIgnoreReturnValue
     public Factory setCompositeSequenceableLoaderFactory(
         CompositeSequenceableLoaderFactory compositeSequenceableLoaderFactory) {
       this.compositeSequenceableLoaderFactory =
@@ -191,6 +196,7 @@ public final class SsMediaSource extends BaseMediaSource
       return this;
     }
 
+    @CanIgnoreReturnValue
     @Override
     public Factory setDrmSessionManagerProvider(
         DrmSessionManagerProvider drmSessionManagerProvider) {

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/TransformationTestResult.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.transformer;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.json.JSONException;
 import org.json.JSONObject;
 
@@ -49,6 +50,7 @@ public class TransformationTestResult {
      * @param filePath The path.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setFilePath(@Nullable String filePath) {
       this.filePath = filePath;
       return this;
@@ -63,6 +65,7 @@ public class TransformationTestResult {
      * @param elapsedTimeMs The time, in ms.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setElapsedTimeMs(long elapsedTimeMs) {
       this.elapsedTimeMs = elapsedTimeMs;
       return this;
@@ -76,6 +79,7 @@ public class TransformationTestResult {
      * @param ssim The structural similarity index.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setSsim(double ssim) {
       this.ssim = ssim;
       return this;
@@ -89,6 +93,7 @@ public class TransformationTestResult {
      * @param analysisException The {@link Exception} thrown during analysis.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setAnalysisException(@Nullable Exception analysisException) {
       this.analysisException = analysisException;
       return this;

library/transformer/src/androidTest/java/com/google/android/exoplayer2/transformer/TransformerAndroidTestRunner.java

@@ -28,6 +28,7 @@ import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.SystemClock;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Ascii;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.File;
 import java.io.IOException;
 import java.util.List;
@@ -77,6 +78,7 @@ public class TransformerAndroidTestRunner {
      * @param timeoutSeconds The timeout.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setTimeoutSeconds(int timeoutSeconds) {
       this.timeoutSeconds = timeoutSeconds;
       return this;
@@ -96,6 +98,7 @@ public class TransformerAndroidTestRunner {
      * @param maybeCalculateSsim Whether to try to calculate SSIM.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setMaybeCalculateSsim(boolean maybeCalculateSsim) {
       this.maybeCalculateSsim = maybeCalculateSsim;
       return this;
@@ -115,6 +118,7 @@ public class TransformerAndroidTestRunner {
      * @param suppressAnalysisExceptions Whether to suppress analysis exceptions.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setSuppressAnalysisExceptions(boolean suppressAnalysisExceptions) {
       this.suppressAnalysisExceptions = suppressAnalysisExceptions;
       return this;
@@ -130,6 +134,7 @@ public class TransformerAndroidTestRunner {
      * @param inputValues A {@link Map} of values to be written to the transformation summary.
      * @return This {@link Builder}.
      */
+    @CanIgnoreReturnValue
     public Builder setInputValues(@Nullable Map<String, Object> inputValues) {
       this.inputValues = inputValues;
       return this;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/DefaultEncoderFactory.java

@@ -37,6 +37,7 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.ColorInfo;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.List;
 import org.checkerframework.checker.nullness.qual.RequiresNonNull;
@@ -69,6 +70,7 @@ public final class DefaultEncoderFactory implements Codec.EncoderFactory {
      *
      * <p>The default value is {@link EncoderSelector#DEFAULT}.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoEncoderSelector(EncoderSelector encoderSelector) {
       this.encoderSelector = encoderSelector;
       return this;
@@ -91,6 +93,7 @@ public final class DefaultEncoderFactory implements Codec.EncoderFactory {
      *
      * <p>The default value is {@link VideoEncoderSettings#DEFAULT}.
      */
+    @CanIgnoreReturnValue
     public Builder setRequestedVideoEncoderSettings(
         VideoEncoderSettings requestedVideoEncoderSettings) {
       this.requestedVideoEncoderSettings = requestedVideoEncoderSettings;
@@ -108,6 +111,7 @@ public final class DefaultEncoderFactory implements Codec.EncoderFactory {
      *
      * <p>The default value is {@code true}.
      */
+    @CanIgnoreReturnValue
     public Builder setEnableFallback(boolean enableFallback) {
       this.enableFallback = enableFallback;
       return this;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/ScaleToFitTransformation.java

@@ -23,6 +23,7 @@ import static java.lang.Math.min;
 import android.graphics.Matrix;
 import android.util.Size;
 import com.google.android.exoplayer2.util.GlUtil;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /**
@@ -59,6 +60,7 @@ public final class ScaleToFitTransformation implements MatrixTransformation {
      * @param scaleY The multiplier by which the frame will scale vertically, along the y-axis.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setScale(float scaleX, float scaleY) {
       this.scaleX = scaleX;
       this.scaleY = scaleY;
@@ -73,6 +75,7 @@ public final class ScaleToFitTransformation implements MatrixTransformation {
      * @param rotationDegrees The counterclockwise rotation, in degrees.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRotationDegrees(float rotationDegrees) {
       this.rotationDegrees = rotationDegrees;
       return this;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationRequest.java

@@ -24,6 +24,7 @@ import com.google.android.exoplayer2.extractor.mp4.Mp4Extractor;
 import com.google.android.exoplayer2.source.MediaSource;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /** A media transformation request. */
 public final class TransformationRequest {
@@ -94,6 +95,7 @@ public final class TransformationRequest {
      * @param flattenForSlowMotion Whether to flatten for slow motion.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setFlattenForSlowMotion(boolean flattenForSlowMotion) {
       this.flattenForSlowMotion = flattenForSlowMotion;
       return this;
@@ -110,6 +112,7 @@ public final class TransformationRequest {
      * @param scaleY The multiplier by which the frame will scale vertically, along the y-axis.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setScale(float scaleX, float scaleY) {
       this.scaleX = scaleX;
       this.scaleY = scaleY;
@@ -128,6 +131,7 @@ public final class TransformationRequest {
      * @param rotationDegrees The counterclockwise rotation, in degrees.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRotationDegrees(float rotationDegrees) {
       this.rotationDegrees = rotationDegrees;
       return this;
@@ -148,6 +152,7 @@ public final class TransformationRequest {
      * @param outputHeight The output height of the displayed video, in pixels.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setResolution(int outputHeight) {
       this.outputHeight = outputHeight;
       return this;
@@ -171,6 +176,7 @@ public final class TransformationRequest {
      * @throws IllegalArgumentException If the {@code videoMimeType} is non-null but not a video
      *     {@linkplain MimeTypes MIME type}.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoMimeType(@Nullable String videoMimeType) {
       checkArgument(
           videoMimeType == null || MimeTypes.isVideo(videoMimeType),
@@ -196,6 +202,7 @@ public final class TransformationRequest {
      * @throws IllegalArgumentException If the {@code audioMimeType} is non-null but not an audio
      *     {@linkplain MimeTypes MIME type}.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioMimeType(@Nullable String audioMimeType) {
       checkArgument(
           audioMimeType == null || MimeTypes.isAudio(audioMimeType),
@@ -215,6 +222,7 @@ public final class TransformationRequest {
      * @param enableRequestSdrToneMapping Whether to request tone-mapping down to SDR.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEnableRequestSdrToneMapping(boolean enableRequestSdrToneMapping) {
       this.enableRequestSdrToneMapping = enableRequestSdrToneMapping;
       return this;
@@ -233,6 +241,7 @@ public final class TransformationRequest {
      *     dynamic range (HDR) signal.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder experimental_setEnableHdrEditing(boolean enableHdrEditing) {
       this.enableHdrEditing = enableHdrEditing;
       return this;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/TransformationResult.java

@@ -19,6 +19,7 @@ import static com.google.android.exoplayer2.util.Assertions.checkArgument;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 
 /** Information about the result of a successful transformation. */
 public final class TransformationResult {
@@ -43,6 +44,7 @@ public final class TransformationResult {
      *
      * <p>Input must be positive or {@link C#TIME_UNSET}.
      */
+    @CanIgnoreReturnValue
     public Builder setDurationMs(long durationMs) {
       checkArgument(durationMs > 0 || durationMs == C.TIME_UNSET);
       this.durationMs = durationMs;
@@ -54,6 +56,7 @@ public final class TransformationResult {
      *
      * <p>Input must be positive or {@link C#LENGTH_UNSET}.
      */
+    @CanIgnoreReturnValue
     public Builder setFileSizeBytes(long fileSizeBytes) {
       checkArgument(fileSizeBytes > 0 || fileSizeBytes == C.LENGTH_UNSET);
       this.fileSizeBytes = fileSizeBytes;
@@ -65,6 +68,7 @@ public final class TransformationResult {
      *
      * <p>Input must be positive or {@link C#RATE_UNSET_INT}.
      */
+    @CanIgnoreReturnValue
     public Builder setAverageAudioBitrate(int averageAudioBitrate) {
       checkArgument(averageAudioBitrate > 0 || averageAudioBitrate == C.RATE_UNSET_INT);
       this.averageAudioBitrate = averageAudioBitrate;
@@ -76,6 +80,7 @@ public final class TransformationResult {
      *
      * <p>Input must be positive or {@link C#RATE_UNSET_INT}.
      */
+    @CanIgnoreReturnValue
     public Builder setAverageVideoBitrate(int averageVideoBitrate) {
       checkArgument(averageVideoBitrate > 0 || averageVideoBitrate == C.RATE_UNSET_INT);
       this.averageVideoBitrate = averageVideoBitrate;
@@ -87,6 +92,7 @@ public final class TransformationResult {
      *
      * <p>Input must be positive or {@code 0}.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoFrameCount(int videoFrameCount) {
       checkArgument(videoFrameCount >= 0);
       this.videoFrameCount = videoFrameCount;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/Transformer.java

@@ -58,6 +58,7 @@ import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.android.exoplayer2.video.VideoRendererEventListener;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.lang.annotation.Documented;
@@ -155,6 +156,7 @@ public final class Transformer {
      * @param transformationRequest The {@link TransformationRequest}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setTransformationRequest(TransformationRequest transformationRequest) {
       this.transformationRequest = transformationRequest;
       return this;
@@ -173,6 +175,7 @@ public final class Transformer {
      * @param effects The {@linkplain GlEffect effects} to apply to each video frame.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoEffects(List<GlEffect> effects) {
       this.videoEffects = ImmutableList.copyOf(effects);
       return this;
@@ -187,6 +190,7 @@ public final class Transformer {
      * @param mediaSourceFactory A {@link MediaSource.Factory}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSourceFactory(MediaSource.Factory mediaSourceFactory) {
       this.mediaSourceFactory = mediaSourceFactory;
       return this;
@@ -203,6 +207,7 @@ public final class Transformer {
      * @param removeAudio Whether to remove the audio.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRemoveAudio(boolean removeAudio) {
       this.removeAudio = removeAudio;
       return this;
@@ -219,6 +224,7 @@ public final class Transformer {
      * @param removeVideo Whether to remove the video.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRemoveVideo(boolean removeVideo) {
       this.removeVideo = removeVideo;
       return this;
@@ -228,6 +234,7 @@ public final class Transformer {
      * @deprecated Use {@link TransformationRequest.Builder#setFlattenForSlowMotion(boolean)}
      *     instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setFlattenForSlowMotion(boolean flattenForSlowMotion) {
       transformationRequest =
@@ -239,6 +246,7 @@ public final class Transformer {
      * @deprecated This feature will be removed in a following release and the MIME type of the
      *     output will always be MP4.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setOutputMimeType(String outputMimeType) {
       this.containerMimeType = outputMimeType;
@@ -249,6 +257,7 @@ public final class Transformer {
      * @deprecated Use {@link #addListener(Listener)}, {@link #removeListener(Listener)} or {@link
      *     #removeAllListeners()} instead.
      */
+    @CanIgnoreReturnValue
     @Deprecated
     public Builder setListener(Transformer.Listener listener) {
       this.listeners.clear();
@@ -264,6 +273,7 @@ public final class Transformer {
      * @param listener A {@link Transformer.Listener}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder addListener(Transformer.Listener listener) {
       this.listeners.add(listener);
       return this;
@@ -277,6 +287,7 @@ public final class Transformer {
      * @param listener A {@link Transformer.Listener}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder removeListener(Transformer.Listener listener) {
       this.listeners.remove(listener);
       return this;
@@ -289,6 +300,7 @@ public final class Transformer {
      *
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder removeAllListeners() {
       this.listeners.clear();
       return this;
@@ -304,6 +316,7 @@ public final class Transformer {
      * @param looper A {@link Looper}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLooper(Looper looper) {
       this.looper = looper;
       this.listeners = listeners.copy(looper, (listener, flags) -> {});
@@ -318,6 +331,7 @@ public final class Transformer {
      * @param encoderFactory The {@link Codec.EncoderFactory} instance.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEncoderFactory(Codec.EncoderFactory encoderFactory) {
       this.encoderFactory = encoderFactory;
       return this;
@@ -331,6 +345,7 @@ public final class Transformer {
      * @param decoderFactory The {@link Codec.DecoderFactory} instance.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setDecoderFactory(Codec.DecoderFactory decoderFactory) {
       this.decoderFactory = decoderFactory;
       return this;
@@ -348,6 +363,7 @@ public final class Transformer {
      * @param debugViewProvider Provider for debug views.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setDebugViewProvider(DebugViewProvider debugViewProvider) {
       this.debugViewProvider = debugViewProvider;
       return this;
@@ -361,6 +377,7 @@ public final class Transformer {
      * @param clock The {@link Clock} instance.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     @VisibleForTesting
     /* package */ Builder setClock(Clock clock) {
       this.clock = clock;
@@ -376,6 +393,7 @@ public final class Transformer {
      * @param muxerFactory A {@link Muxer.Factory}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     @VisibleForTesting
     /* package */ Builder setMuxerFactory(Muxer.Factory muxerFactory) {
       this.muxerFactory = muxerFactory;

library/transformer/src/main/java/com/google/android/exoplayer2/transformer/VideoEncoderSettings.java

@@ -29,6 +29,7 @@ import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import com.google.android.exoplayer2.Format;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -104,6 +105,7 @@ public final class VideoEncoderSettings {
      * @param bitrate The {@link VideoEncoderSettings#bitrate}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setBitrate(int bitrate) {
       this.bitrate = bitrate;
       return this;
@@ -118,6 +120,7 @@ public final class VideoEncoderSettings {
      * @param bitrateMode The {@link VideoEncoderSettings#bitrateMode}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setBitrateMode(@BitrateMode int bitrateMode) {
       checkArgument(bitrateMode == BITRATE_MODE_VBR || bitrateMode == BITRATE_MODE_CBR);
       this.bitrateMode = bitrateMode;
@@ -138,6 +141,7 @@ public final class VideoEncoderSettings {
      * @param encodingLevel The {@link VideoEncoderSettings#level}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setEncodingProfileLevel(int encodingProfile, int encodingLevel) {
       this.profile = encodingProfile;
       this.level = encodingLevel;
@@ -151,6 +155,7 @@ public final class VideoEncoderSettings {
      * @param iFrameIntervalSeconds The {@link VideoEncoderSettings#iFrameIntervalSeconds}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setiFrameIntervalSeconds(float iFrameIntervalSeconds) {
       this.iFrameIntervalSeconds = iFrameIntervalSeconds;
       return this;
@@ -164,6 +169,7 @@ public final class VideoEncoderSettings {
      * @param priority The {@link MediaFormat#KEY_PRIORITY priority}.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     @VisibleForTesting
     public Builder setEncoderPerformanceParameters(int operatingRate, int priority) {
       this.operatingRate = operatingRate;
@@ -180,6 +186,7 @@ public final class VideoEncoderSettings {
      *
      * <p>Can not be enabled alongside setting a custom bitrate with {@link #setBitrate(int)}.
      */
+    @CanIgnoreReturnValue
     public Builder setEnableHighQualityTargeting(boolean enableHighQualityTargeting) {
       this.enableHighQualityTargeting = enableHighQualityTargeting;
       return this;

playbacktests/src/androidTest/java/com/google/android/exoplayer2/playbacktests/gts/DashTestRunner.java

@@ -59,6 +59,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Log;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.primitives.Ints;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -128,16 +129,19 @@ import java.util.List;
     this.activity = activity;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setStreamName(String streamName) {
     this.streamName = streamName;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setFullPlaybackNoSeeking(boolean fullPlaybackNoSeeking) {
     this.fullPlaybackNoSeeking = fullPlaybackNoSeeking;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setCanIncludeAdditionalVideoFormats(
       boolean canIncludeAdditionalVideoFormats) {
     this.canIncludeAdditionalVideoFormats =
@@ -145,27 +149,32 @@ import java.util.List;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setActionSchedule(ActionSchedule actionSchedule) {
     this.actionSchedule = actionSchedule;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setOfflineLicenseKeySetId(byte[] offlineLicenseKeySetId) {
     this.offlineLicenseKeySetId = offlineLicenseKeySetId;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setAudioVideoFormats(String audioFormat, String... videoFormats) {
     this.audioFormat = audioFormat;
     this.videoFormats = videoFormats;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setManifestUrl(String manifestUrl) {
     this.manifestUrl = manifestUrl;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setWidevineInfo(String mimeType, boolean videoIdRequiredInLicenseUrl) {
     this.useL1Widevine = isL1WidevineAvailable(mimeType);
     this.widevineLicenseUrl =
@@ -173,6 +182,7 @@ import java.util.List;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public DashTestRunner setDataSourceFactory(DataSource.Factory dataSourceFactory) {
     this.dataSourceFactory = dataSourceFactory;
     return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/ActionSchedule.java

@@ -56,6 +56,7 @@ import com.google.android.exoplayer2.testutil.Action.WaitForTimelineChanged;
 import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.HandlerWrapper;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /** Schedules a sequence of {@link Action}s for execution during a test. */
@@ -127,6 +128,7 @@ public final class ActionSchedule {
      * @param delayMs The delay in milliseconds.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder delay(long delayMs) {
       currentDelayMs += delayMs;
       return this;
@@ -138,6 +140,7 @@ public final class ActionSchedule {
      * @param action The action to schedule.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder apply(Action action) {
       return appendActionNode(new ActionNode(action, currentDelayMs));
     }
@@ -149,6 +152,7 @@ public final class ActionSchedule {
      * @param intervalMs The interval between each repetition in milliseconds.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder repeat(Action action, long intervalMs) {
       return appendActionNode(new ActionNode(action, currentDelayMs, intervalMs));
     }
@@ -159,6 +163,7 @@ public final class ActionSchedule {
      * @param positionMs The seek position.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder seek(long positionMs) {
       return apply(new Seek(tag, positionMs));
     }
@@ -170,6 +175,7 @@ public final class ActionSchedule {
      * @param positionMs The seek position.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder seek(int mediaItemIndex, long positionMs) {
       return apply(
           new Seek(tag, mediaItemIndex, positionMs, /* catchIllegalSeekException= */ false));
@@ -183,6 +189,7 @@ public final class ActionSchedule {
      * @param catchIllegalSeekException Whether an illegal seek position should be caught or not.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder seek(int mediaItemIndex, long positionMs, boolean catchIllegalSeekException) {
       return apply(new Seek(tag, mediaItemIndex, positionMs, catchIllegalSeekException));
     }
@@ -206,6 +213,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForPendingPlayerCommands() {
       return apply(new WaitForPendingPlayerCommands(tag));
     }
@@ -217,6 +225,7 @@ public final class ActionSchedule {
      * @return The builder, for convenience.
      * @see Player#setPlaybackParameters(PlaybackParameters)
      */
+    @CanIgnoreReturnValue
     public Builder setPlaybackParameters(PlaybackParameters playbackParameters) {
       return apply(new SetPlaybackParameters(tag, playbackParameters));
     }
@@ -226,6 +235,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder stop() {
       return apply(new Stop(tag));
     }
@@ -236,6 +246,7 @@ public final class ActionSchedule {
      * @param reset Whether the player should be reset.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder stop(boolean reset) {
       return apply(new Stop(tag, reset));
     }
@@ -245,6 +256,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder play() {
       return apply(new SetPlayWhenReady(tag, true));
     }
@@ -257,6 +269,7 @@ public final class ActionSchedule {
      * @param positionMs The position in that media item at which the player should be paused again.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder playUntilPosition(int mediaItemIndex, long positionMs) {
       return apply(new PlayUntilPosition(tag, mediaItemIndex, positionMs));
     }
@@ -268,6 +281,7 @@ public final class ActionSchedule {
      * @param mediaItemIndex The media item index at which the player should be paused again.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder playUntilStartOfMediaItem(int mediaItemIndex) {
       return apply(new PlayUntilPosition(tag, mediaItemIndex, /* positionMs= */ 0));
     }
@@ -277,6 +291,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder pause() {
       return apply(new SetPlayWhenReady(tag, false));
     }
@@ -286,6 +301,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder enableRenderer(int index) {
       return apply(new SetRendererDisabled(tag, index, false));
     }
@@ -295,6 +311,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder disableRenderer(int index) {
       return apply(new SetRendererDisabled(tag, index, true));
     }
@@ -304,6 +321,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder clearVideoSurface() {
       return apply(new ClearVideoSurface(tag));
     }
@@ -313,6 +331,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoSurface() {
       return apply(new SetVideoSurface(tag));
     }
@@ -322,6 +341,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setAudioAttributes(AudioAttributes audioAttributes, boolean handleAudioFocus) {
       return apply(new SetAudioAttributes(tag, audioAttributes, handleAudioFocus));
     }
@@ -337,6 +357,7 @@ public final class ActionSchedule {
      *     parameter is ignored.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSources(int mediaItemIndex, long positionMs, MediaSource... sources) {
       return apply(new Action.SetMediaItems(tag, mediaItemIndex, positionMs, sources));
     }
@@ -347,6 +368,7 @@ public final class ActionSchedule {
      * @param resetPosition Whether the playback position should be reset.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSources(boolean resetPosition, MediaSource... sources) {
       return apply(new Action.SetMediaItemsResetPosition(tag, resetPosition, sources));
     }
@@ -357,6 +379,7 @@ public final class ActionSchedule {
      * @param mediaSources The media sources to add.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSources(MediaSource... mediaSources) {
       return apply(
           new Action.SetMediaItems(
@@ -371,6 +394,7 @@ public final class ActionSchedule {
      * @param mediaSources The media sources to add.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder addMediaSources(MediaSource... mediaSources) {
       return apply(new Action.AddMediaItems(tag, mediaSources));
     }
@@ -382,6 +406,7 @@ public final class ActionSchedule {
      * @param newIndex The index after the item has been moved.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder moveMediaItem(int currentIndex, int newIndex) {
       return apply(new Action.MoveMediaItem(tag, currentIndex, newIndex));
     }
@@ -392,6 +417,7 @@ public final class ActionSchedule {
      * @param index The index of the media item to be removed.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder removeMediaItem(int index) {
       return apply(new Action.RemoveMediaItem(tag, index));
     }
@@ -403,6 +429,7 @@ public final class ActionSchedule {
      * @param toIndex The end of the range of media items to be removed (exclusive).
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder removeMediaItems(int fromIndex, int toIndex) {
       return apply(new Action.RemoveMediaItems(tag, fromIndex, toIndex));
     }
@@ -412,6 +439,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder prepare() {
       return apply(new Action.Prepare(tag));
     }
@@ -421,6 +449,7 @@ public final class ActionSchedule {
      *
      * @return The builder. for convenience,
      */
+    @CanIgnoreReturnValue
     public Builder clearMediaItems() {
       return apply(new Action.ClearMediaItems(tag));
     }
@@ -430,6 +459,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setRepeatMode(@Player.RepeatMode int repeatMode) {
       return apply(new SetRepeatMode(tag, repeatMode));
     }
@@ -440,6 +470,7 @@ public final class ActionSchedule {
      * @param shuffleOrder The shuffle order.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setShuffleOrder(ShuffleOrder shuffleOrder) {
       return apply(new SetShuffleOrder(tag, shuffleOrder));
     }
@@ -449,6 +480,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder setShuffleModeEnabled(boolean shuffleModeEnabled) {
       return apply(new SetShuffleModeEnabled(tag, shuffleModeEnabled));
     }
@@ -460,6 +492,7 @@ public final class ActionSchedule {
      *     in milliseconds.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder sendMessage(Target target, long positionMs) {
       return apply(new SendMessages(tag, target, positionMs));
     }
@@ -472,6 +505,7 @@ public final class ActionSchedule {
      * @param positionMs The position at which the message should be sent, in milliseconds.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder sendMessage(Target target, int mediaItemIndex, long positionMs) {
       return apply(
           new SendMessages(
@@ -487,6 +521,7 @@ public final class ActionSchedule {
      * @param deleteAfterDelivery Whether the message will be deleted after delivery.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder sendMessage(
         Target target, int mediaItemIndex, long positionMs, boolean deleteAfterDelivery) {
       return apply(new SendMessages(tag, target, mediaItemIndex, positionMs, deleteAfterDelivery));
@@ -497,6 +532,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForTimelineChanged() {
       return apply(new WaitForTimelineChanged(tag));
     }
@@ -508,6 +544,7 @@ public final class ActionSchedule {
      * @param expectedReason The expected reason of the timeline change.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForTimelineChanged(
         Timeline expectedTimeline, @Player.TimelineChangeReason int expectedReason) {
       return apply(new WaitForTimelineChanged(tag, expectedTimeline, expectedReason));
@@ -518,6 +555,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForPositionDiscontinuity() {
       return apply(new WaitForPositionDiscontinuity(tag));
     }
@@ -528,6 +566,7 @@ public final class ActionSchedule {
      * @param targetPlayWhenReady The target playWhenReady value.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForPlayWhenReady(boolean targetPlayWhenReady) {
       return apply(new WaitForPlayWhenReady(tag, targetPlayWhenReady));
     }
@@ -538,6 +577,7 @@ public final class ActionSchedule {
      * @param targetPlaybackState The target playback state.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForPlaybackState(@Player.State int targetPlaybackState) {
       return apply(new WaitForPlaybackState(tag, targetPlaybackState));
     }
@@ -548,6 +588,7 @@ public final class ActionSchedule {
      * @param targetIsLoading The target value of {@code player.isLoading()}.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForIsLoading(boolean targetIsLoading) {
       return apply(new WaitForIsLoading(tag, targetIsLoading));
     }
@@ -558,6 +599,7 @@ public final class ActionSchedule {
      * @param playerTarget The target to observe.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder waitForMessage(PlayerTarget playerTarget) {
       return apply(new WaitForMessage(tag, playerTarget));
     }
@@ -567,6 +609,7 @@ public final class ActionSchedule {
      *
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder executeRunnable(Runnable runnable) {
       return apply(new ExecuteRunnable(tag, runnable));
     }
@@ -577,6 +620,7 @@ public final class ActionSchedule {
      * @param exception The exception to throw.
      * @return The builder, for convenience.
      */
+    @CanIgnoreReturnValue
     public Builder throwPlaybackException(ExoPlaybackException exception) {
       return apply(new ThrowPlaybackException(tag, exception));
     }
@@ -588,6 +632,7 @@ public final class ActionSchedule {
       return new ActionSchedule(rootNode, callbackAction);
     }
 
+    @CanIgnoreReturnValue
     private Builder appendActionNode(ActionNode actionNode) {
       previousNode.setNext(actionNode);
       previousNode = actionNode;

testutils/src/main/java/com/google/android/exoplayer2/testutil/CacheAsserts.java

@@ -29,6 +29,7 @@ import com.google.android.exoplayer2.upstream.cache.Cache;
 import com.google.android.exoplayer2.upstream.cache.CacheDataSource;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 
@@ -50,6 +51,7 @@ public final class CacheAsserts {
       }
     }
 
+    @CanIgnoreReturnValue
     public RequestSet subset(String... uriStrings) {
       dataSpecs = new DataSpec[uriStrings.length];
       for (int i = 0; i < dataSpecs.length; i++) {
@@ -58,6 +60,7 @@ public final class CacheAsserts {
       return this;
     }
 
+    @CanIgnoreReturnValue
     public RequestSet subset(Uri... uris) {
       dataSpecs = new DataSpec[uris.length];
       for (int i = 0; i < dataSpecs.length; i++) {
@@ -66,6 +69,7 @@ public final class CacheAsserts {
       return this;
     }
 
+    @CanIgnoreReturnValue
     public RequestSet subset(DataSpec... dataSpecs) {
       this.dataSpecs = dataSpecs;
       return this;
@@ -83,6 +87,7 @@ public final class CacheAsserts {
       return dataSpecs[i];
     }
 
+    @CanIgnoreReturnValue
     public RequestSet useBoundedDataSpecFor(String uriString) {
       FakeData data = Assertions.checkStateNotNull(fakeDataSet.getData(uriString));
       for (int i = 0; i < dataSpecs.length; i++) {

testutils/src/main/java/com/google/android/exoplayer2/testutil/DataSourceContractTest.java

@@ -42,6 +42,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Ascii;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
@@ -662,17 +663,20 @@ public abstract class DataSourceContractTest {
       /**
        * Sets a human-readable name for this resource which will be shown in test failure messages.
        */
+      @CanIgnoreReturnValue
       public Builder setName(String name) {
         this.name = name;
         return this;
       }
 
       /** Sets the URI where this resource is located. */
+      @CanIgnoreReturnValue
       public Builder setUri(String uri) {
         return setUri(Uri.parse(uri));
       }
 
       /** Sets the URI where this resource is located. */
+      @CanIgnoreReturnValue
       public Builder setUri(Uri uri) {
         this.uri = uri;
         return this;
@@ -683,6 +687,7 @@ public abstract class DataSourceContractTest {
        *
        * <p>Must be at least 5 bytes.
        */
+      @CanIgnoreReturnValue
       public Builder setExpectedBytes(byte[] expectedBytes) {
         checkArgument(expectedBytes.length >= 5);
         this.expectedBytes = expectedBytes;

testutils/src/main/java/com/google/android/exoplayer2/testutil/DownloadBuilder.java

@@ -22,6 +22,7 @@ import com.google.android.exoplayer2.offline.Download;
 import com.google.android.exoplayer2.offline.DownloadProgress;
 import com.google.android.exoplayer2.offline.DownloadRequest;
 import com.google.android.exoplayer2.offline.StreamKey;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -109,6 +110,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#uri
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setUri(String uri) {
     this.uri = Uri.parse(uri);
     return this;
@@ -117,6 +119,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#uri
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setUri(Uri uri) {
     this.uri = uri;
     return this;
@@ -125,6 +128,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#mimeType
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setMimeType(String mimeType) {
     this.mimeType = mimeType;
     return this;
@@ -133,6 +137,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#keySetId
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setKeySetId(byte[] keySetId) {
     this.keySetId = keySetId;
     return this;
@@ -141,6 +146,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#customCacheKey
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setCacheKey(@Nullable String cacheKey) {
     this.cacheKey = cacheKey;
     return this;
@@ -149,6 +155,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#state
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setState(@Download.State int state) {
     this.state = state;
     return this;
@@ -157,6 +164,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadProgress#percentDownloaded
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setPercentDownloaded(float percentDownloaded) {
     progress.percentDownloaded = percentDownloaded;
     return this;
@@ -165,6 +173,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadProgress#bytesDownloaded
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setBytesDownloaded(long bytesDownloaded) {
     progress.bytesDownloaded = bytesDownloaded;
     return this;
@@ -173,6 +182,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#contentLength
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setContentLength(long contentLength) {
     this.contentLength = contentLength;
     return this;
@@ -181,6 +191,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#failureReason
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setFailureReason(int failureReason) {
     this.failureReason = failureReason;
     return this;
@@ -189,6 +200,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#stopReason
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setStopReason(int stopReason) {
     this.stopReason = stopReason;
     return this;
@@ -197,6 +209,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#startTimeMs
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setStartTimeMs(long startTimeMs) {
     this.startTimeMs = startTimeMs;
     return this;
@@ -205,6 +218,7 @@ public final class DownloadBuilder {
   /**
    * @see Download#updateTimeMs
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setUpdateTimeMs(long updateTimeMs) {
     this.updateTimeMs = updateTimeMs;
     return this;
@@ -213,6 +227,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#streamKeys
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setStreamKeys(StreamKey... streamKeys) {
     this.streamKeys = Arrays.asList(streamKeys);
     return this;
@@ -221,6 +236,7 @@ public final class DownloadBuilder {
   /**
    * @see DownloadRequest#data
    */
+  @CanIgnoreReturnValue
   public DownloadBuilder setCustomMetadata(byte[] customMetadata) {
     this.customMetadata = customMetadata;
     return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/Dumper.java

@@ -17,6 +17,7 @@ package com.google.android.exoplayer2.testutil;
 
 import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.Arrays;
 import java.util.Locale;
 
@@ -42,15 +43,18 @@ public final class Dumper {
     sb = new StringBuilder();
   }
 
+  @CanIgnoreReturnValue
   public Dumper add(String field, @Nullable Object value) {
     return addString(field + " = " + value + '\n');
   }
 
+  @CanIgnoreReturnValue
   public Dumper add(Dumpable object) {
     object.dump(this);
     return this;
   }
 
+  @CanIgnoreReturnValue
   public Dumper add(String field, @Nullable byte[] value) {
     String string =
         String.format(
@@ -62,16 +66,19 @@ public final class Dumper {
     return addString(string);
   }
 
+  @CanIgnoreReturnValue
   public Dumper addTime(String field, long time) {
     return add(field, time == C.TIME_UNSET ? "UNSET TIME" : time);
   }
 
+  @CanIgnoreReturnValue
   public Dumper startBlock(String name) {
     addString(name + ":\n");
     indent += INDENT_SIZE_IN_SPACES;
     return this;
   }
 
+  @CanIgnoreReturnValue
   public Dumper endBlock() {
     indent -= INDENT_SIZE_IN_SPACES;
     return this;
@@ -82,6 +89,7 @@ public final class Dumper {
     return sb.toString();
   }
 
+  @CanIgnoreReturnValue
   private Dumper addString(String string) {
     for (int i = 0; i < indent; i++) {
       sb.append(' ');

testutils/src/main/java/com/google/android/exoplayer2/testutil/ExoPlayerTestRunner.java

@@ -43,6 +43,7 @@ import com.google.android.exoplayer2.util.Clock;
 import com.google.android.exoplayer2.util.HandlerWrapper;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -109,6 +110,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      *     runner.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setTimeline(Timeline timeline) {
       assertThat(mediaSources).isEmpty();
       assertFalse(skipSettingMediaSources);
@@ -124,6 +126,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param manifest A manifest to be used by a {@link FakeMediaSource} in the test runner.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setManifest(Object manifest) {
       assertThat(mediaSources).isEmpty();
       assertFalse(skipSettingMediaSources);
@@ -138,6 +141,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param positionMs The position in milliseconds to seek to.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder initialSeek(int mediaItemIndex, long positionMs) {
       this.initialMediaItemIndex = mediaItemIndex;
       this.initialPositionMs = positionMs;
@@ -154,6 +158,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param mediaSources The {@link MediaSource}s to be used by the test runner.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setMediaSources(MediaSource... mediaSources) {
       assertThat(timeline).isNull();
       assertThat(manifest).isNull();
@@ -171,6 +176,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param supportedFormats A list of supported {@link Format}s.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setSupportedFormats(Format... supportedFormats) {
       this.supportedFormats = supportedFormats;
       return this;
@@ -183,6 +189,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      *
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder skipSettingMediaSources() {
       assertThat(timeline).isNull();
       assertThat(manifest).isNull();
@@ -195,6 +202,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setUseLazyPreparation(boolean)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setUseLazyPreparation(boolean useLazyPreparation) {
       testPlayerBuilder.setUseLazyPreparation(useLazyPreparation);
       return this;
@@ -206,6 +214,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param pauseAtEndOfMediaItems Whether to pause at the end of media items.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPauseAtEndOfMediaItems(boolean pauseAtEndOfMediaItems) {
       this.pauseAtEndOfMediaItems = pauseAtEndOfMediaItems;
       return this;
@@ -215,6 +224,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setTrackSelector(DefaultTrackSelector)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setTrackSelector(DefaultTrackSelector trackSelector) {
       testPlayerBuilder.setTrackSelector(trackSelector);
       return this;
@@ -224,6 +234,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setLoadControl(LoadControl)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setLoadControl(LoadControl loadControl) {
       testPlayerBuilder.setLoadControl(loadControl);
       return this;
@@ -233,6 +244,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setBandwidthMeter(BandwidthMeter)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setBandwidthMeter(BandwidthMeter bandwidthMeter) {
       this.testPlayerBuilder.setBandwidthMeter(bandwidthMeter);
       return this;
@@ -242,6 +254,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setRenderers(Renderer...)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRenderers(Renderer... renderers) {
       testPlayerBuilder.setRenderers(renderers);
       return this;
@@ -251,6 +264,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setRenderersFactory(RenderersFactory)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setRenderersFactory(RenderersFactory renderersFactory) {
       testPlayerBuilder.setRenderersFactory(renderersFactory);
       return this;
@@ -260,6 +274,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @see TestExoPlayerBuilder#setClock(Clock)
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setClock(Clock clock) {
       testPlayerBuilder.setClock(clock);
       return this;
@@ -272,6 +287,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param actionSchedule An {@link ActionSchedule} to be used by the test runner.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setActionSchedule(ActionSchedule actionSchedule) {
       this.actionSchedule = actionSchedule;
       return this;
@@ -283,6 +299,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param surface The {@link Surface} to be used by the player.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setVideoSurface(Surface surface) {
       this.surface = surface;
       return this;
@@ -295,6 +312,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      *     to player events.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setPlayerListener(Player.Listener playerListener) {
       this.playerListener = playerListener;
       return this;
@@ -306,6 +324,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      * @param analyticsListener An {@link AnalyticsListener} to be registered.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setAnalyticsListener(AnalyticsListener analyticsListener) {
       this.analyticsListener = analyticsListener;
       return this;
@@ -320,6 +339,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
      *     or idle state.
      * @return This builder.
      */
+    @CanIgnoreReturnValue
     public Builder setExpectedPlayerEndedCount(int expectedPlayerEndedCount) {
       this.expectedPlayerEndedCount = expectedPlayerEndedCount;
       return this;
@@ -429,6 +449,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
    *
    * @return This test runner.
    */
+  @CanIgnoreReturnValue
   public ExoPlayerTestRunner start() {
     return start(/* doPrepare= */ true);
   }
@@ -440,6 +461,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
    * @param doPrepare Whether the player should be prepared.
    * @return This test runner.
    */
+  @CanIgnoreReturnValue
   public ExoPlayerTestRunner start(boolean doPrepare) {
     handler.post(
         () -> {
@@ -494,6 +516,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
    * @return This test runner.
    * @throws Exception If any exception occurred during playback, release, or due to a timeout.
    */
+  @CanIgnoreReturnValue
   public ExoPlayerTestRunner blockUntilEnded(long timeoutMs) throws Exception {
     clock.onThreadBlocked();
     if (!endedCountDownLatch.await(timeoutMs, MILLISECONDS)) {
@@ -516,6 +539,7 @@ public final class ExoPlayerTestRunner implements Player.Listener, ActionSchedul
    * @throws TimeoutException If the action schedule did not finish within the specified timeout.
    * @throws InterruptedException If the test thread gets interrupted while waiting.
    */
+  @CanIgnoreReturnValue
   public ExoPlayerTestRunner blockUntilActionScheduleFinished(long timeoutMs)
       throws TimeoutException, InterruptedException {
     clock.onThreadBlocked();

testutils/src/main/java/com/google/android/exoplayer2/testutil/ExtractorAsserts.java

@@ -32,6 +32,7 @@ import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
@@ -145,11 +146,13 @@ public final class ExtractorAsserts {
       private @MonotonicNonNull String dumpFilesPrefix;
       private boolean deduplicateConsecutiveFormats;
 
+      @CanIgnoreReturnValue
       public Builder setDumpFilesPrefix(String dumpFilesPrefix) {
         this.dumpFilesPrefix = dumpFilesPrefix;
         return this;
       }
 
+      @CanIgnoreReturnValue
       public Builder setDeduplicateConsecutiveFormats(boolean deduplicateConsecutiveFormats) {
         this.deduplicateConsecutiveFormats = deduplicateConsecutiveFormats;
         return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeDataSet.java

@@ -20,6 +20,7 @@ import androidx.annotation.Nullable;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.util.Assertions;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
@@ -152,12 +153,14 @@ public class FakeDataSet {
      * the {@link DataSpec#length} of the argument, including the case where the length is equal to
      * {@link C#LENGTH_UNSET}.
      */
+    @CanIgnoreReturnValue
     public FakeData setSimulateUnknownLength(boolean simulateUnknownLength) {
       this.simulateUnknownLength = simulateUnknownLength;
       return this;
     }
 
     /** Appends to the underlying data. */
+    @CanIgnoreReturnValue
     public FakeData appendReadData(byte[] data) {
       Assertions.checkState(data.length > 0);
       segments.add(new Segment(data, getLastSegment()));
@@ -168,6 +171,7 @@ public class FakeDataSet {
      * Appends a data segment of the specified length. No actual data is available and the {@link
      * FakeDataSource} will perform no copy operations when this data is read.
      */
+    @CanIgnoreReturnValue
     public FakeData appendReadData(int length) {
       Assertions.checkState(length > 0);
       segments.add(new Segment(length, getLastSegment()));
@@ -175,12 +179,14 @@ public class FakeDataSet {
     }
 
     /** Appends an error in the underlying data. */
+    @CanIgnoreReturnValue
     public FakeData appendReadError(IOException exception) {
       segments.add(new Segment(exception, getLastSegment()));
       return this;
     }
 
     /** Appends an action. */
+    @CanIgnoreReturnValue
     public FakeData appendReadAction(Runnable action) {
       segments.add(new Segment(action, getLastSegment()));
       return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeDataSource.java

@@ -30,6 +30,7 @@ import com.google.android.exoplayer2.upstream.DataSourceException;
 import com.google.android.exoplayer2.upstream.DataSpec;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.IOException;
 import java.util.ArrayList;
 
@@ -49,11 +50,13 @@ public class FakeDataSource extends BaseDataSource {
       fakeDataSet = new FakeDataSet();
     }
 
+    @CanIgnoreReturnValue
     public final Factory setFakeDataSet(FakeDataSet fakeDataSet) {
       this.fakeDataSet = fakeDataSet;
       return this;
     }
 
+    @CanIgnoreReturnValue
     public final Factory setIsNetwork(boolean isNetwork) {
       this.isNetwork = isNetwork;
       return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeExoMediaDrm.java

@@ -39,6 +39,7 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.primitives.Bytes;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -83,6 +84,7 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
      *
      * <p>Defaults to true.
      */
+    @CanIgnoreReturnValue
     public Builder setEnforceValidKeyResponses(boolean enforceValidKeyResponses) {
       this.enforceValidKeyResponses = enforceValidKeyResponses;
       return this;
@@ -98,6 +100,7 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
      *
      * <p>Defaults to 0 (i.e. device is already provisioned).
      */
+    @CanIgnoreReturnValue
     public Builder setProvisionsRequired(int provisionsRequired) {
       this.provisionsRequired = provisionsRequired;
       return this;
@@ -108,6 +111,7 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
      * {@link #getKeyRequest(byte[], List, int, HashMap)} instead of the default behaviour of
      * throwing from {@link #openSession()}.
      */
+    @CanIgnoreReturnValue
     public Builder throwNotProvisionedExceptionFromGetKeyRequest() {
       this.throwNotProvisionedExceptionFromGetKeyRequest = true;
       return this;
@@ -121,6 +125,7 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
      *
      * <p>Defaults to {@link Integer#MAX_VALUE}.
      */
+    @CanIgnoreReturnValue
     public Builder setMaxConcurrentSessions(int maxConcurrentSessions) {
       this.maxConcurrentSessions = maxConcurrentSessions;
       return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeExtractorInput.java

@@ -22,6 +22,7 @@ import android.util.SparseBooleanArray;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.extractor.ExtractorInput;
 import com.google.android.exoplayer2.util.Util;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.io.EOFException;
 import java.io.IOException;
 
@@ -291,21 +292,25 @@ public final class FakeExtractorInput implements ExtractorInput {
       data = Util.EMPTY_BYTE_ARRAY;
     }
 
+    @CanIgnoreReturnValue
     public Builder setData(byte[] data) {
       this.data = data;
       return this;
     }
 
+    @CanIgnoreReturnValue
     public Builder setSimulateUnknownLength(boolean simulateUnknownLength) {
       this.simulateUnknownLength = simulateUnknownLength;
       return this;
     }
 
+    @CanIgnoreReturnValue
     public Builder setSimulatePartialReads(boolean simulatePartialReads) {
       this.simulatePartialReads = simulatePartialReads;
       return this;
     }
 
+    @CanIgnoreReturnValue
     public Builder setSimulateIOErrors(boolean simulateIOErrors) {
       this.simulateIOErrors = simulateIOErrors;
       return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/TestExoPlayerBuilder.java

@@ -33,6 +33,7 @@ import com.google.android.exoplayer2.upstream.BandwidthMeter;
 import com.google.android.exoplayer2.upstream.DefaultBandwidthMeter;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Clock;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
 
 /** A builder of {@link ExoPlayer} instances for testing. */
@@ -71,6 +72,7 @@ public class TestExoPlayerBuilder {
    * @param useLazyPreparation Whether to use lazy preparation.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setUseLazyPreparation(boolean useLazyPreparation) {
     this.useLazyPreparation = useLazyPreparation;
     return this;
@@ -88,6 +90,7 @@ public class TestExoPlayerBuilder {
    * @param trackSelector The {@link DefaultTrackSelector} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setTrackSelector(DefaultTrackSelector trackSelector) {
     Assertions.checkNotNull(trackSelector);
     this.trackSelector = trackSelector;
@@ -106,6 +109,7 @@ public class TestExoPlayerBuilder {
    * @param loadControl The {@link LoadControl} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setLoadControl(LoadControl loadControl) {
     this.loadControl = loadControl;
     return this;
@@ -123,6 +127,7 @@ public class TestExoPlayerBuilder {
    * @param bandwidthMeter The {@link BandwidthMeter} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setBandwidthMeter(BandwidthMeter bandwidthMeter) {
     Assertions.checkNotNull(bandwidthMeter);
     this.bandwidthMeter = bandwidthMeter;
@@ -142,6 +147,7 @@ public class TestExoPlayerBuilder {
    * @param renderers A list of {@link Renderer}s to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setRenderers(Renderer... renderers) {
     assertThat(renderersFactory).isNull();
     this.renderers = renderers;
@@ -167,6 +173,7 @@ public class TestExoPlayerBuilder {
    * @param renderersFactory A {@link RenderersFactory} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setRenderersFactory(RenderersFactory renderersFactory) {
     assertThat(renderers).isNull();
     this.renderersFactory = renderersFactory;
@@ -189,6 +196,7 @@ public class TestExoPlayerBuilder {
    * @param clock A {@link Clock} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setClock(Clock clock) {
     assertThat(clock).isNotNull();
     this.clock = clock;
@@ -206,6 +214,7 @@ public class TestExoPlayerBuilder {
    * @param looper The {@link Looper} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setLooper(Looper looper) {
     this.looper = looper;
     return this;
@@ -235,6 +244,7 @@ public class TestExoPlayerBuilder {
    * @param mediaSourceFactory The {@link MediaSource.Factory} to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setMediaSourceFactory(MediaSource.Factory mediaSourceFactory) {
     this.mediaSourceFactory = mediaSourceFactory;
     return this;
@@ -246,6 +256,7 @@ public class TestExoPlayerBuilder {
    * @param seekBackIncrementMs The seek back increment to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setSeekBackIncrementMs(long seekBackIncrementMs) {
     this.seekBackIncrementMs = seekBackIncrementMs;
     return this;
@@ -262,6 +273,7 @@ public class TestExoPlayerBuilder {
    * @param seekForwardIncrementMs The seek forward increment to be used by the player.
    * @return This builder.
    */
+  @CanIgnoreReturnValue
   public TestExoPlayerBuilder setSeekForwardIncrementMs(long seekForwardIncrementMs) {
     this.seekForwardIncrementMs = seekForwardIncrementMs;
     return this;

testutils/src/main/java/com/google/android/exoplayer2/testutil/WebServerDispatcher.java

@@ -32,6 +32,7 @@ import com.google.common.base.Strings;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Maps;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import java.lang.annotation.Documented;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
@@ -118,6 +119,7 @@ public class WebServerDispatcher extends Dispatcher {
        *
        * @return this builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public Builder setPath(String path) {
         this.path = path.startsWith("/") ? path : "/" + path;
         return this;
@@ -128,6 +130,7 @@ public class WebServerDispatcher extends Dispatcher {
        *
        * @return this builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public Builder setData(byte[] data) {
         this.data = data;
         return this;
@@ -138,6 +141,7 @@ public class WebServerDispatcher extends Dispatcher {
        *
        * @return this builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public Builder supportsRangeRequests(boolean supportsRangeRequests) {
         this.supportsRangeRequests = supportsRangeRequests;
         return this;
@@ -151,6 +155,7 @@ public class WebServerDispatcher extends Dispatcher {
        *
        * @return this builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public Builder resolvesToUnknownLength(boolean resolvesToUnknownLength) {
         this.resolvesToUnknownLength = resolvesToUnknownLength;
         return this;
@@ -162,6 +167,7 @@ public class WebServerDispatcher extends Dispatcher {
        *
        * @return this builder, for convenience.
        */
+      @CanIgnoreReturnValue
       public Builder setGzipSupport(@GzipSupport int gzipSupport) {
         this.gzipSupport = gzipSupport;
         return this;