Akka.Streams.Tests.Dsl.FlowSplitWhenSpec.SplitWhen_must_work_with_single_element_splits C# (CSharp) Method

        public void SplitWhen_must_work_with_single_element_splits()
        {
            this.AssertAllStagesStopped(() =>
            {
                var task = Source.From(Enumerable.Range(1, 100))
                    .SplitWhen(_ => true)
                    .Lift()
                    .SelectAsync(1, s => s.RunWith(Sink.First<int>(), Materializer)) // Please note that this line *also* implicitly asserts nonempty substreams
                    .Grouped(200)
                    .RunWith(Sink.First<IEnumerable<int>>(), Materializer);
                task.Wait(TimeSpan.FromSeconds(3)).Should().BeTrue();
                task.Result.ShouldAllBeEquivalentTo(Enumerable.Range(1, 100));
            }, Materializer);
        }