code: @Override
      public void step(SimState arg0) {
          logger.finest("Notifying each element of the notifable element list...");
          for(Notifable n: NotificationManager.notifables){
              NotificationManager.addNotification(n);
          }
      }
docs: When the setp of NotificationManager its called generates a notification for each notifable
  that has been added to it.