static class Subscriber {
    final List<Object> nonSubscriberEvents = new ArrayList<>();
    final List<Object> subscriberEvents = new ArrayList<>();

    public void notASubscriber(Object o) {
      nonSubscriberEvents.add(o);
    }

    @Subscribe
    public void subscriber(Object o) {
      subscriberEvents.add(o);
    }
  }

  public void testNonSubscriber() {