ExtJS drag/drop a CompositeSprite

I want to set draggable on a CompositeSprite using Ext JS 4.0. There are examples on how I can set draggable a single sprite (draggable: true), but it doesn't work for CompositeSprite. If I wr开发者_StackOverflow社区ite:

compositeSprite.setAttributes({
  draggable: true
});

the result is each sprite in compositeSprite can be dragged separately. I need them to be dragged together.

I have also tried to use dd property which contains Ext.dd.DragSource, but I can't apply Ext.dd.DragSource to Sprites. (There are no examples on the net, only for grid and tree).

Any thoughts?