@Override
 public TextureRegion getTexture(AssetManager manager) {
   return holder.getTexture(manager);
 }
 @Override
 public void dispose() {
   holder.dispose();
 }
 @Override
 public void unloadSource(AssetManager manager) {
   holder.unloadSource(manager);
 }
 @Override
 public String getSource() {
   return holder.getSource();
 }