@Override
 public void localRender(OrchidContext oc) throws IOException, OrchidException {
   if (isExpanded()) {
     foldImage.render(oc);
     foldTrigger.render(oc);
   } else {
     expandImage.render(oc);
     expandTrigger.render(oc);
   }
 }
  OAjaxTrigger initAjaxTriggerAndListener(
      OrchidContext oc, StandardAjaxEventListener listener, OWidget target) throws OrchidException {
    OAjaxTrigger oAjaxTriggerOnClick = new OAjaxTriggerOnEvent(target, JsEventTriggerType.CLICK);
    oAjaxTriggerOnClick.setFormPostSource(this);
    addAndInitChild(oc, oAjaxTriggerOnClick);

    getTree().registerAjaxEventListener(target, listener);

    return oAjaxTriggerOnClick;
  }