public ReliableTopicConfig addMessageListenerConfig(ListenerConfig listenerConfig) {
        checkNotNull(listenerConfig, "listenerConfig can't be null");
        listenerConfigs.add(listenerConfig);
        return this;
    }
@Test(expected = NullPointerException.class)
    public void addMessageListenerConfig_whenNull() {
        ReliableTopicConfig config = new ReliableTopicConfig("foo");

        config.addMessageListenerConfig(null);
    }