In Menu, I dont want to close the sub menu item on click of sub menu

Webix JS
#1

https://snippet.webix.com/a1b51b5a In Given snippet on click of the sub menu item, the sub menu popup is getting closed , I dont want to close the sub menu onclick of sub menu item

#2

try this

  on:{
    onMenuItemClick:function(id, e){
      webix.message("Click: "+this.getMenuItem(id).value);
      if(!this.getSubMenu(id))//has no child item
        return webix.html.preventEvent(e);
    }
  },