actorBus.subscribe(subscriber2, observer1);
actorBus.subscribe(subscriber2, observer2);
Notification n1 = new Notification(observer1, 100);
actorBus.publish(n1);
probe1.expectMsgEquals(n1);
probe2.expectMsgEquals(n1);
Notification n2 = new Notification(observer2, 101);
actorBus.publish(n2);
probe2.expectMsgEquals(n2);
probe1.expectNoMsg(FiniteDuration.create(500, TimeUnit.MILLISECONDS));
//#actor-bus-test