code: <T> T actorFor(final Class<T> protocol, final Definition definition, final Actor parent, final Supervisor maybeSupervisor, final Logger logger) {
      ActorProtocolActor<T> actor = actorProtocolFor(protocol, definition, parent, null, null, maybeSupervisor, logger);
      return actor.protocolActor();
    }
docs: Answers the T protocol for the newly created Actor instance. (INTERNAL ONLY)
  @param <T> the protocol type
  @param protocol the {@code Class<T>} protocol of the Actor
  @param definition the Definition of the Actor
  @param parent the Actor parent of this Actor
  @param maybeSupervisor the possible Supervisor of this Actor
  @param logger the Logger of this Actor
  @return T