@Test
public void testGetTopicNamesReturnsImmutable() {

    final List<TopicListing> topicListingList = new ArrayList<>();
    topicListingList.add(new TopicListing("A", false));
    topicListingList.add(new TopicListing("B", false));
    topicListingList.add(new TopicListing("C", false));
    // Create instance
    final TopicList topicList = new TopicList(topicListingList);
    final List<String> results = topicList.getTopicNames();
    // Should be immutable.
    expectedException.expect(UnsupportedOperationException.class);
    results.remove(1);
}