    @Test
    @DisplayName("obtain methods subscribed to events of the passed class and the class of origin")
    void subscribersOf() {

        ImmutableSet<SubscriberMethod> methods = subscriberClass.subscribersOf(
                EventClass.from(SpeakerJoined.class), EmptyClass.instance());

        assertThat(methods).hasSize(1);
        SubscriberMethod actual = getFirst(methods, null);
        assertThat(actual.rawMethod())
            .isEqualTo(getMethod(ConferenceProgram.class, "addSpeaker"));
    }