@Test
public void testAction0() {

    final AtomicInteger value = new AtomicInteger();
    Action0 action = new Action0() {
        @Override
        public void call() {
            value.incrementAndGet();
        }
    };
    Async.toAsync(action, Schedulers.immediate())
            .call()
            .subscribe(new TestObserver<Object>(observer));
    verify(observer, never()).onError(any(Throwable.class));
    verify(observer, times(1)).onNext(null);
    verify(observer, times(1)).onCompleted();
    Assert.assertEquals(1, value.get());
}