### Question:
NotificationInteractor extends ValueInteractor<Notification> { @Override protected Observable<Notification> provideUpdateObservable() { return Observable.just(null); } NotificationInteractor(@NonNull final Context context); void clear(); void onNext(@NonNull final Notification notification); Observable<Notification> filter(@NonNull @Notification.Type final String type);  }### Answer:
@Test public void provideUpdateObservable() throws Exception { final Notification result = Sync.last(notificationInteractor.provideUpdateObservable()); assertNull(result); }