@Test
public void testTakeLast2() {

    Observable<String> w = Observable.from("one");
    Observable<String> take = Observable.create(takeLast(w, 10));
    @SuppressWarnings("unchecked")
    Observer<String> observer = mock(Observer.class);
    take.subscribe(observer);
    verify(observer, times(1)).onNext("one");
    verify(observer, never()).onError(any(Throwable.class));
    verify(observer, times(1)).onCompleted();
}