public void PrefixAndTail_must_work_on_empty_input()
{
this.AssertAllStagesStopped(() =>
{
var futureSink = NewHeadSink;
var fut = Source.Empty<int>().PrefixAndTail(10).RunWith(futureSink, Materializer);
fut.Wait(TimeSpan.FromSeconds(3)).Should().BeTrue();
var tailFlow = fut.Result.Item2;
var tailSubscriber = TestSubscriber.CreateManualProbe<int>(this);
tailFlow.To(Sink.FromSubscriber(tailSubscriber)).Run(Materializer);
tailSubscriber.ExpectSubscriptionAndComplete();
}, Materializer);
}