/**
  * @see org.olat.core.gui.control.DefaultController#event(org.olat.core.gui.UserRequest,
  *     org.olat.core.gui.components.Component, org.olat.core.gui.control.Event)
  */
 @Override
 @SuppressWarnings("unused")
 public void event(final UserRequest ureq, final Component source, final Event event) {
   if (source == startNotifyButton) {
     NotificationsManager.getInstance().notifyAllSubscribersByEmail();
   }
 }
 @Override
 public void cleanupOnDelete(final ICourse course) {
   // mark the subscription to this node as deleted
   final SubscriptionContext subsContext =
       WikiManager.createTechnicalSubscriptionContextForCourse(
           course.getCourseEnvironment(), this);
   NotificationsManager.getInstance().delete(subsContext);
 }