code: 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;
      }
docs: Called to broadcast message on MBeanServer event bus.  Internally, it calls
  NotificationBroadCasterSupport.sendNotification() method to dispatch the event.
  
  @param data - a data object sent as part of the event parameter.
  @return a sequence number associated with the emitted event.