void start() {
      if (myTimerImpl != null) {
        stop();
      }

      myTimerImpl = new TimerListener() {
        @Override
        public ModalityState getModalityState() {
          return ModalityState.current();
        }

        @Override
        public void run() {
          updateActionItems();
        }
      };
      ActionManager.getInstance().addTimerListener(myTimerImpl);
    }
void start()