public void ActorMaterializer_should_shut_down_supervisor_actor_it_encapsulates()
{
var m = Sys.Materializer() as ActorMaterializerImpl;
Source.From(Enumerable.Empty<object>()).To(Sink.Ignore<object>()).Run(m);
m.Supervisor.Tell(StreamSupervisor.GetChildren.Instance);
ExpectMsg<StreamSupervisor.Children>();
m.Shutdown();
m.Supervisor.Tell(StreamSupervisor.GetChildren.Instance);
ExpectNoMsg(TimeSpan.FromSeconds(1));
}