docs: public long getLoopDurationMs() {
      if (mAnimationBackend == null) {
        return 0;
      }
      if (mFrameScheduler != null) {
        return mFrameScheduler.getLoopDurationMs();
      }
      int loopDurationMs = 0;
      for (int i = 0; i < mAnimationBackend.getFrameCount(); i++) {
        loopDurationMs += mAnimationBackend.getFrameDurationMs(i);
      }
      return loopDurationMs;
    }