Akka.Streams.Tests.Dsl.GraphUnzipSpec.A_Unzip_must_cancel_upstream_when_downstream_cancel C# (CSharp) Method

        public void A_Unzip_must_cancel_upstream_when_downstream_cancel()
        {
            this.AssertAllStagesStopped(() =>
            {
                var p1 = TestPublisher.CreateManualProbe<KeyValuePair<int, string>>(this);
                var c1 = TestSubscriber.CreateManualProbe<int>(this);
                var c2 = TestSubscriber.CreateManualProbe<string>(this);

                RunnableGraph.FromGraph(GraphDsl.Create(b =>
                {
                    var unzip = b.Add(new UnZip<int, string>());
                    var source = Source.FromPublisher(p1.Publisher);

                    b.From(source).To(unzip.In);
                    b.From(unzip.Out0).To(Sink.FromSubscriber(c1));
                    b.From(unzip.Out1).To(Sink.FromSubscriber(c2));

                    return ClosedShape.Instance;
                })).Run(Materializer);

                var p1Sub = p1.ExpectSubscription();
                var sub1 = c1.ExpectSubscription();
                var sub2 = c2.ExpectSubscription();

                sub1.Request(3);
                sub2.Request(3);
                p1.ExpectRequest(p1Sub, 16);
                p1Sub.SendNext(new KeyValuePair<int, string>(1, "a"));
                c1.ExpectNext(1);
                c2.ExpectNext("a");
                p1Sub.SendNext(new KeyValuePair<int, string>(2, "b"));
                c1.ExpectNext(2);
                c2.ExpectNext("b");
                sub1.Cancel();
                sub2.Cancel();
                p1Sub.ExpectCancellation();
            }, Materializer);
        }