@Test
  public void lightService_requestFavourites() {
    List<LightModel> lights = new ArrayList<>();

    mockClient();
    when(lightRepository.findFavourites()).thenReturn(Observable.just(lights));

    TestSubscriber<List<LightModel>> tester = new TestSubscriber<>();
    lightService.requestFavourites().subscribe(tester);

    tester.assertValue(lights);
    tester.assertCompleted();
    tester.assertNoErrors();
  }