Akka.Streams.Tests.Dsl.ReverseArrowSpec.Reverse_Arrows_in_the_GraphDsl_must_fail_towards_already_full_UniformFanOutShape C# (CSharp) Method

        public void Reverse_Arrows_in_the_GraphDsl_must_fail_towards_already_full_UniformFanOutShape()
        {
            var task = RunnableGraph.FromGraph(GraphDsl.Create(Sink, (b, s) =>
            {
                var f = b.Add(new Broadcast<int>(2));
                var sink2 = b.Add(Streams.Dsl.Sink.Ignore<int>().MapMaterializedValue(_ => MaterializedValue));
                var src = b.Add(Source);
                b.From(src).To(f);
                b.To(sink2).From(f);

                b.Invoking(builder => builder.To(s).Via(f).From(src))
                    .ShouldThrow<ArgumentException>()
                    .WithMessage("The output port [StatefulSelectMany.out] is already connected");

                return ClosedShape.Instance;
            })).Run(Materializer);
            task.Wait(TimeSpan.FromSeconds(1)).Should().BeTrue();
            task.Result.ShouldAllBeEquivalentTo(new[] { 1, 2, 3 });
        }