@Test public void testFirstWithPredicateOfNoneMatchingThePredicate() { Observable<Integer> observable = Observable.just(1, 3, 5, 7, 9, 7, 5, 3, 1); observable.filter(IS_EVEN).first().subscribe(w); verify(w, never()).onNext(anyInt()); verify(w, never()).onComplete(); verify(w, times(1)).onError(isA(NoSuchElementException.class)); }