@Override
  public void scheduleDrawable(@NonNull Drawable who, @NonNull Runnable what, long when) {
    Callback callback = getCallback();
    if (callback == null) {
      return;
    }
    callback.scheduleDrawable(this, what, when);
  }
These Drawable.Callback methods proxy the calls so that this is the drawable that is
actually invalidated, not a child one which will not pass the view's validateDrawable check.
lottie/src/main/java/com/airbnb/lottie/LottieDrawable.java