public void Failed_Source_must_emit_error_immediately()
{
var ex = new SystemException();
var p = Source.Failed<int>(ex).RunWith(Sink.AsPublisher<int>(false), Materializer);
var c = TestSubscriber.CreateManualProbe<int>(this);
p.Subscribe(c);
c.ExpectSubscriptionAndError();
//reject additional subscriber
var c2 = TestSubscriber.CreateManualProbe<int>(this);
p.Subscribe(c2);
c2.ExpectSubscriptionAndError();
}