Akka.NET layered hierarchy with custom supervisor strategy

Example.cs

public class CustomException : Exception { }
public class Boom { }
public class Grandpa : ReceiveActor
{
    public Grandpa()
    {
        var parent = Context.ActorOf(Props.Create<Parent>(), "parent");
        ReceiveAny(x => parent.Forward(x));
    }

    protected override SupervisorStrategy SupervisorStrategy()
    {
        return new OneForOneStrategy(10, 10, exception =>
        {
            if (exception is CustomException)
            {
                Console.WriteLine("Custom exception received");
                return Directive.Stop;
            }
            else return Akka.Actor.SupervisorStrategy.DefaultDecider(exception);
        });
    }
}

public class Parent : UntypedActor
{
    public Parent()
    {
        Context.ActorOf(Props.Create<Child>(), "child-1");
        Context.ActorOf(Props.Create<Child>(), "child-2");
        Context.ActorOf(Props.Create<Child>(), "child-3");
    }

    protected override void OnReceive(object message)
    {
        if(message is Boom) throw new CustomException();
        else
            foreach (var child in Context.GetChildren())
            {
                child.Forward(message);
            }
    }
}

public class Child : UntypedActor
{
    protected override void OnReceive(object message)
    {
        Console.WriteLine("{0} received {1}", Self, message);
    }

    protected override void PreStart()
    {
        Console.WriteLine("{0} is starting", Self);
        base.PreStart();
    }

    protected override void PostStop()
    {
        Console.WriteLine("{0} is stopping", Self);
        base.PostStop();
    }
}

class Program
{
    static void Main(string[] args)
    {
        using (var system = ActorSystem.Create("sys"))
        {
            var grandpa = system.ActorOf(Props.Create<Grandpa>(), "grandpa");
            grandpa.Tell("ok");
            grandpa.Tell(new Boom());

            Console.ReadLine();
        }
    }
}