private async Task<Tuple<Subject2Ref, IActorRef>> SetupActors2(LogBoard<string> log)
{
var subjectActor = ActorOfAsTestActorRef<Subject2Actor>("Subject");
var subject = subjectActor.Cast<Subject2Ref>();
var observingActor = ActorOf(() => new TestExceptionActor(log));
await subject.Subscribe(new Subject2Observer(new AkkaReceiverNotificationChannel(observingActor)));
return Tuple.Create(subject, (IActorRef)observingActor);
}