docs: public long send(Object data) {
          long seq = NumberSequencer.getNextSequence();
          Notification note = new Notification(
                  this.getEvent(),
                  this,
                  seq,
                  System.currentTimeMillis(),
                  "Event notification " + this.getEvent()
          );
          note.setUserData(data);
          super.sendNotification(note);
          return seq;
      }