code: public void createUUID(final AsyncCallback<CmsUUID> callback) {
  
          // do not stop/start since we do not want to give any feedback to the user
          CmsRpcAction<CmsUUID> action = new CmsRpcAction<CmsUUID>() {
  
              /**
               * @see org.opencms.gwt.client.rpc.CmsRpcAction#execute()
               */
              @Override
              public void execute() {
  
                  getService().createUUID(this);
              }
  
              /**
               * @see org.opencms.gwt.client.rpc.CmsRpcAction#onResponse(java.lang.Object)
               */
              @Override
              protected void onResponse(CmsUUID result) {
  
                  callback.onSuccess(result);
              }
          };
          action.execute();
      }
docs: Creates a new CmsUUID.<p>
  
  @param callback the callback to execute