@Override
 protected void onError(AjaxRequestTarget target, Form<?> form) {
   EventUtils.addFeedbackPanel(this, target);
   target.add(form);
 }
 @Override
 protected void onSubmit(AjaxRequestTarget target, Form<?> form) {
   EventUtils.addFeedbackPanel(this, target);
   listener.onClick(this, target);
 }