public AskSpec(ITestOutputHelper output) : base(output) { this.behavior = Behaviors.Receive <Msg>(async(ctx, msg) => { switch (msg.Type) { case MessageType.Foo: msg.ReplyTo.Tell("foo"); return(Behaviors.Same <Msg>()); case MessageType.Stop: msg.ReplyTo.Tell("stopped"); return(Behaviors.Stopped <Msg>()); default: throw new NotImplementedException(); } ; }); }