@Test
public void testConcatWithList() {

    @SuppressWarnings("unchecked")
    Observer<String> observer = mock(Observer.class);
    final String[] o = { "1", "3", "5", "7" };
    final String[] e = { "2", "4", "6" };
    final Observable<String> odds = Observable.from(o);
    final Observable<String> even = Observable.from(e);
    final List<Observable<String>> list = new ArrayList<Observable<String>>();
    list.add(odds);
    list.add(even);
    Observable<String> concat = Observable.create(concat(list));
    concat.subscribe(observer);
    verify(observer, times(7)).onNext(anyString());
}