assertEquals(
        "One correct event should be delivered.", Lists.newArrayList(EVENT), catcher2.getEvents());

    bus.unregister(catcher1);
    bus.post(EVENT);

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher1.getEvents());

    assertEquals(
        "One correct event should be delivered.", Lists.newArrayList(EVENT), catcher2.getEvents());

    bus.unregister(catcher1);
    bus.post(EVENT);

    assertEquals(
        "Shouldn't catch any more events when unregistered.", expectedEvents, catcher1.getEvents());

    StringCatcher catcher = new StringCatcher();
    bus.register(catcher);

    // We post the event, but our Executor will not deliver it until instructed.
    bus.post(EVENT);

    List<String> events = catcher.getEvents();
    assertTrue("No events should be delivered synchronously.", events.isEmpty());

    // Now we find the task in our Executor and explicitly activate it.
    List<Runnable> tasks = executor.getTasks();