text: var ExpandSubMenu = function (parentButton, items) {
      this.collapseSubMenu();
      var subMenu = new this.constructor(this.scene, {
          items: items,
          orientation: this.orientation,
          createButtonCallback: this.root.createButtonCallback,
          createButtonCallbackScope: this.root.createButtonCallbackScope,
          easeIn: this.root.easeIn,
          easeOut: this.root.easeOut,
  
          root: this.root,
          parent: parentButton
      });
      this.add(subMenu, null);
      this.childrenMap.subMenu = subMenu;    
      return this;
  }
  
  export default ExpandSubMenu;