0 * _

        when:
        manager.getBroadcaster(TestBarListener.class).bar(12)

        then:
        1 * barListener1.bar(12)
        0 * _
    }

    def listenerCanImplementMultipleTypes() {
        given:
        def listener = Mock(BothListener)
        manager.addListener(listener)

        when:
        manager.getBroadcaster(TestFooListener.class).foo("param")