@Test
public void shouldMergeInSecondSource() {

  final Repository<List<Integer>> repository = repositoryWithInitialValue(INITIAL_VALUE)
      .observe()
      .onUpdatesPerLoop()
      .getFrom(listSource)
      .thenMergeIn(otherListSource, new ListMerger<Integer, Integer, Integer>())
      .compile();
  updatable.addToObservable(repository);
  assertThat(repository, has(LIST_AND_OTHER_LIST));
}