// TODO: do we really need this?
// It seems the sender is never null but it doesn't hurt to check. If the caller passes in
// a null sender (ActorRef.noSender()), akka translates that to the deadLetters actor.
// TODO: do we really need this?
// It seems the sender is never null but it doesn't hurt to check. If the caller passes in
// a null sender (ActorRef.noSender()), akka translates that to the deadLetters actor.