docs: public void reverse() {
          mPlayingBackwards = !mPlayingBackwards;
          if (mPlayingState == RUNNING) {
              long currentTime = AnimationUtils.currentAnimationTimeMillis();
              long currentPlayTime = currentTime - mStartTime;
              long timeLeft = mDuration - currentPlayTime;
              mStartTime = currentTime - timeLeft;
          } else {
              start(true);
          }
      }