docs: static ScaleTypeDrawable wrapChildWithScaleType(
        DrawableParent parent, ScalingUtils.ScaleType scaleType) {
      Drawable child = parent.setDrawable(sEmptyDrawable);
      child = maybeWrapWithScaleType(child, scaleType);
      parent.setDrawable(child);
      Preconditions.checkNotNull(child, "Parent has no child drawable!");
      return (ScaleTypeDrawable) child;
    }