
The previous API allowed to pass in null to the constructors although variants without listeners exist. That's why we need to handle these null values. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=191577891
The previous API allowed to pass in null to the constructors although variants without listeners exist. That's why we need to handle these null values. ------------- Created by MOE: https://github.com/google/moe MOE_MIGRATED_REVID=191577891