Akka.Cluster.Tests.StartupWithOneThreadSpec.A_cluster_must_startup_with_one_dispatcher_thread C# (CSharp) Method

        public void A_cluster_must_startup_with_one_dispatcher_thread()
        {
            // This test failed before fixing https://github.com/akkadotnet/akka.net/issues/1959 when adding a sleep before the
            // Await of GetClusterCoreRef in the Cluster extension constructor.
            // The reason was that other cluster actors were started too early and
            // they also tried to get the Cluster extension and thereby blocking
            // dispatcher threads.
            // Note that the Cluster extension is started via ClusterActorRefProvider
            // before ActorSystem.apply returns, i.e. in the constructor of AkkaSpec.
            var totalStartupTime = TimeSpan.FromTicks(MonotonicClock.GetTicks() - _startTime).TotalMilliseconds;
            Assert.True(totalStartupTime < (Sys.Settings.CreationTimeout - TimeSpan.FromSeconds(2)).TotalMilliseconds);
            Sys.ActorOf(TestProps).Tell("hello");
            Sys.ActorOf(TestProps).Tell("hello");
            Sys.ActorOf(TestProps).Tell("hello");

            var cluster = Cluster.Get(Sys);
            totalStartupTime = TimeSpan.FromTicks(MonotonicClock.GetTicks() - _startTime).TotalMilliseconds;
            Assert.True(totalStartupTime < (Sys.Settings.CreationTimeout - TimeSpan.FromSeconds(2)).TotalMilliseconds);

            ExpectMsg("hello");
            ExpectMsg("hello");
            ExpectMsg("hello");
        }
    }