public void PrefixAndTail_must_shut_down_main_stage_if_substream_is_empty_even_when_not_subscribed()
{
this.AssertAllStagesStopped(() =>
{
var futureSink = NewHeadSink;
var fut = Source.Single(1).PrefixAndTail(1).RunWith(futureSink, Materializer);
fut.Wait(TimeSpan.FromSeconds(3)).Should().BeTrue();
fut.Result.Item1.Should().ContainSingle(i => i == 1);
}, Materializer);
}