@Test
@SuppressWarnings("unchecked")
public void testDematerialize1() {

    Observable<Notification<Integer>> notifications = Observable.from(1, 2).materialize();
    Observable<Integer> dematerialize = notifications.dematerialize();
    Observer<Integer> observer = mock(Observer.class);
    dematerialize.subscribe(observer);
    verify(observer, times(1)).onNext(1);
    verify(observer, times(1)).onNext(2);
    verify(observer, times(1)).onCompleted();
    verify(observer, never()).onError(any(Throwable.class));
}