assertEquals(1, Iterators.size(registry.getSubscribers(1)));

    registry.register(new IntegerSubscriber());
    assertEquals(3, Iterators.size(registry.getSubscribers("")));
    assertEquals(1, Iterators.size(registry.getSubscribers(new Object())));
    assertEquals(2, Iterators.size(registry.getSubscribers(1)));
  }

  public void testGetSubscribers_returnsImmutableSnapshot() {

    assertEquals(1, Iterators.size(registry.getSubscribers(1)));

    registry.register(new IntegerSubscriber());
    assertEquals(3, Iterators.size(registry.getSubscribers("")));
    assertEquals(1, Iterators.size(registry.getSubscribers(new Object())));
    assertEquals(2, Iterators.size(registry.getSubscribers(1)));
  }

  public void testGetSubscribers_returnsImmutableSnapshot() {

  }

  /**
   * Gets an iterator representing an immutable snapshot of all subscribers to the given event at
   * the time this method is called.
   */
  Iterator<Subscriber> getSubscribers(Object event) {
    ImmutableSet<Class<?>> eventTypes = flattenHierarchy(event.getClass());

    List<Iterator<Subscriber>> subscriberIterators =
        Lists.newArrayListWithCapacity(eventTypes.size());

      overriddenAndAnnotatedInSubclassEvents.add(o);
    }
  }

  public void testOverriddenAndAnnotatedInSubclass() {
    assertThat(getSubscriber().overriddenAndAnnotatedInSubclassEvents).contains(EVENT);
  }

  public void testOverriddenInSubclassNowhereAnnotated() {
    assertThat(getSubscriber().overriddenInSubclassNowhereAnnotatedEvents).isEmpty();
  }

  @Override
  SubClass createSubscriber() {
    return new SubClass();

      overriddenAndAnnotatedInSubclassEvents.add(o);
    }
  }

  public void testOverriddenAndAnnotatedInSubclass() {
    assertThat(getSubscriber().overriddenAndAnnotatedInSubclassEvents).contains(EVENT);
  }

  public void testOverriddenInSubclassNowhereAnnotated() {
    assertThat(getSubscriber().overriddenInSubclassNowhereAnnotatedEvents).isEmpty();
  }

  @Override
  SubClass createSubscriber() {
    return new SubClass();

  /** Returns the event object that caused the subscriber to throw. */
  public Object getEvent() {
    return event;
  }

  /** Returns the object context that the subscriber was called on. */
  public Object getSubscriber() {
    return subscriber;
  }

  /** Returns the subscribed method that threw the exception. */
  public Method getSubscriberMethod() {
    return subscriberMethod;
  }

 * @author Louis Wasserman
 */
abstract class AbstractEventBusTest<H> extends TestCase {
  static final Object EVENT = new Object();

  abstract H createSubscriber();

  private @Nullable H subscriber;

  H getSubscriber() {
    return subscriber;
  }

  @Override
  protected void setUp() throws Exception {
    subscriber = createSubscriber();
    EventBus bus = new EventBus();
    bus.register(subscriber);