public void A_Sum_must_work_when_using_Flow_Sum()
{
this.AssertAllStagesStopped(() =>
{
var t = InputSource.Via(SumFlow).RunWith(Sink.First<int>(), Materializer);
t.Wait(TimeSpan.FromSeconds(3)).Should().BeTrue();
t.Result.Should().Be(Expected);
}, Materializer);
}