docs: public void setAnimationBackend(@Nullable AnimationBackend animationBackend) {
      mAnimationBackend = animationBackend;
      if (mAnimationBackend != null) {
        mFrameScheduler = new DropFramesFrameScheduler(mAnimationBackend);
        mAnimationBackend.setBounds(getBounds());
        if (mDrawableProperties != null) {
          // re-apply to the same drawable so that the animation backend is updated.
          mDrawableProperties.applyTo(this);
        }
      }
      mFrameScheduler = createSchedulerForBackendAndDelayMethod(mAnimationBackend);
      stop();
    }