private Drawable getDrawable(int drawableResId) {
    Drawable drawable = mCache.get(drawableResId);
    if (drawable == null) {
      drawable = mResources.getDrawable(drawableResId);
      mCache.put(drawableResId, drawable);
    }
    return drawable;
  }
Local drawable animation backend that chains local drawables together.
samples/animation2/src/main/java/com/facebook/samples/animation2/local/LocalDrawableAnimationBackend.java