public void cancelAll() {
   NotificationManager notificationManager =
       (NotificationManager) getContext().getSystemService(Context.NOTIFICATION_SERVICE);
   for (TrayNotification notification : NotificationContainer.getInstance()) {
     notificationManager.cancel(notification.getId());
   }
 }
  public void notify(TrayNotification notificationItem, Class activity) {
    // Get a reference to the NotificationManager:
    NotificationManager notificationManager =
        (NotificationManager) getContext().getSystemService(Context.NOTIFICATION_SERVICE);
    // Instantiate the Notification:
    Notification notification =
        new Notification(getIcon(), notificationItem.getTickerText(), notificationItem.getWhen());

    // Define the Notification's expanded message and Intent:
    Intent notificationIntent = new Intent(getContext(), activity);
    PendingIntent contentIntent = PendingIntent.getActivity(getContext(), 0, notificationIntent, 0);

    notification.setLatestEventInfo(
        getContext(), notificationItem.getTitle(), notificationItem.getMessage(), contentIntent);

    // Pass the Notification to the NotificationManager:
    notificationManager.notify(notificationItem.getId(), notification);
    // That's it. Your user has now been notified.
  }
 public void cancel(TrayNotification notificationItem) {
   NotificationManager notificationManager =
       (NotificationManager) getContext().getSystemService(Context.NOTIFICATION_SERVICE);
   notificationManager.cancel(notificationItem.getId());
 }