@Test
public void shouldNotReturnInvalidReactiveStreamWhenNoWorldFound() throws Exception {

  SearchServerInteractor.Params emptyParams = SearchServerInteractor.Params.empty();
  when(searchServerService.searchServer()).thenReturn(Observable.empty());
  Observable reactiveStream = searchServerInteractor.buildReactiveStream(emptyParams);
  assertThat(reactiveStream).isNotNull();
}