assertEquals(1, registry.getSubscribersForTesting(Object.class).size());
  }

  public void testUnregister() {
    StringSubscriber s1 = new StringSubscriber();
    StringSubscriber s2 = new StringSubscriber();

    registry.register(s1);
    registry.register(s2);

    registry.unregister(s1);
    assertEquals(1, registry.getSubscribersForTesting(String.class).size());

          subscriber(bus, i2, "handleInteger", Integer.class),
          subscriber(bus, i3, "handleInteger", Integer.class));

  private final StringSubscriber s1 = new StringSubscriber("s1");
  private final StringSubscriber s2 = new StringSubscriber("s2");
  private final ImmutableList<Subscriber> stringSubscribers =
      ImmutableList.of(
          subscriber(bus, s1, "handleString", String.class),