@Test
public void testWhileDoSourceThrows() {

    Observable<Integer> source1 = Observable.concat(Observable.from(1, 2, 3),
            Observable.<Integer> error(new RuntimeException("Forced failure!")));
    Observable<Integer> result = Statement.whileDo(source1, condition);
    observeError(result, RuntimeException.class, 1, 2, 3);
}