@Test
public void testSendTopicChangeMessage() {

    final Topic topic = new Topic("Interesting changed topic", "Snoopy", 2132321323L);
    final String message = "(" + topic.getNick() + ")" +
            "[" + topic.getTime() + "]" +
            topic.getTopic();
    messages.sendTopicChangeMessage(topic);
    verify(service).sendMessageToAllUsers(createMessage("TOPIC") + message);
}