@Override
 protected void addWidget(MenuItem wrapped, Widget isWidget) {
   if (isWidget instanceof MenuBar) {
     wrapped.setSubMenu((MenuBar) isWidget);
   } else {
     super.addWidget(wrapped, isWidget);
   }
 }
    @Override
    protected void appendElement(
        DockLayoutPanel wrapped, Element element, String namespaceURI, List<Widget> childWidgets) {

      if (!UiBinderXmlUtils.CLIENTUI_NSURI.equals(namespaceURI)) {
        super.appendElement(wrapped, element, namespaceURI, childWidgets);
      } else {
        handleDockLayoutPanelSpecifics(wrapped, element, childWidgets);
      }
    }