code: public void checkNewWidgetsAvailable(final CmsUUID structureId, final AsyncCallback<Boolean> resultCallback) {
  
          CmsRpcAction<Boolean> action = new CmsRpcAction<Boolean>() {
  
              @Override
              public void execute() {
  
                  start(200, false);
                  getContainerpageService().checkNewWidgetsAvailable(structureId, this);
              }
  
              @Override
              protected void onResponse(Boolean result) {
  
                  stop(false);
                  resultCallback.onSuccess(result);
              }
  
              // empty
          };
          action.execute();
  
      }
docs: Checks whether GWT widgets are available for all fields of a content.<p>
  
  @param structureId the structure id of the content
  @param resultCallback the callback for the result