Akka.Streams.Tests.Dsl.FlowSelectManySpec.SelectMany_should_map_and_concat_grouping_with_slow_downstream C# (CSharp) Method

        public void SelectMany_should_map_and_concat_grouping_with_slow_downstream()
        {
            var subscriber = this.CreateManualProbe<int>();
            var input = new[]
            {
                new[] {1, 2, 3, 4, 5},
                new[] {6, 7, 8, 9, 10},
                new[] {11, 12, 13, 14, 15},
                new[] {16, 17, 18, 19, 20},
            };

            Source
                .From(input)
                .SelectMany(x => x)
                .Select(x =>
                {
                    Thread.Sleep(10);
                    return x;
                })
                .RunWith(Sink.FromSubscriber(subscriber), materializer);

            var subscription = subscriber.ExpectSubscription();
            subscription.Request(100);
            for (int i = 1; i <= 20; i++)
                subscriber.ExpectNext(i);

            subscriber.ExpectComplete();
        }