Akka.Streams.Tests.Dsl.FlowThrottleSpec.Throttle_for_various_cost_elements_must_burst_some_elements_if_have_enough_time C# (CSharp) Method

        public void Throttle_for_various_cost_elements_must_burst_some_elements_if_have_enough_time()
        {
            this.AssertAllStagesStopped(() =>
            {
                var upstream = TestPublisher.CreateProbe<int>(this);
                var downstream = TestSubscriber.CreateProbe<int>(this);

                Source.FromPublisher(upstream)
                    .Throttle(2, TimeSpan.FromMilliseconds(400), 5, e => e < 4 ? 1 : 20, ThrottleMode.Shaping)
                    .RunWith(Sink.FromSubscriber(downstream), Materializer);

                downstream.Request(1);
                upstream.SendNext(1);
                downstream.ExpectNoMsg(TimeSpan.FromMilliseconds(100));
                downstream.ExpectNext(1);
                downstream.ExpectNoMsg(TimeSpan.FromMilliseconds(500)); //wait to receive 2 in burst afterwards
                downstream.Request(5);
                var expected = new List<OnNext>();
                for (var i = 2; i < 5; i++)
                {
                    upstream.SendNext(i);
                    if (i < 4)
                        expected.Add(new OnNext(i));
                }
                downstream.ReceiveWhile(TimeSpan.FromMilliseconds(200), filter: x => x, msgs: 2)
                    .ShouldAllBeEquivalentTo(expected);

                downstream.Cancel();
            }, Materializer);
        }