public void testSingleSubscriberOneEvent() {
    Event1 event;
    bus.register(subscriber);

    bus.post(event = new Event1("event1"));
    subscriber.assertSameEvents(event);
  }
 public void testProducerFirst() {
   bus.register(producer);
   bus.register(subscriber);
   subscriber.assertSameEvents(producer.lastEvent);
 }