@Test
public void testFunc1() {

    Func1<Integer, Integer> func = new Func1<Integer, Integer>() {
        @Override
        public Integer call(Integer t1) {
            return t1;
        }
    };
    Async.toAsync(func, Schedulers.immediate())
            .call(1)
            .subscribe(new TestObserver<Object>(observer));
    verify(observer, never()).onError(any(Throwable.class));
    verify(observer, times(1)).onNext(1);
    verify(observer, times(1)).onCompleted();
}