code: function MenuItem (opts) {
      MenuItem.superclass.constructor.call(this, opts)
  
      var callback = opts.callback
  
      this.anchorPoint = ccp(0.5, 0.5)
      this.callback = callback
  }
docs: @class
  Base class for any buttons or options in a menu
  
  @memberOf cocos.nodes
  @extends cocos.nodes.Node
  
  @opt {Function} callback Function to call when menu item is activated