code: public final void initActor(String path, ActorContext context, Mailbox mailbox) {
          this.path = path;
          this.context = context;
          this.mailbox = mailbox;
      }
docs: <p>INTERNAL API</p>
  Initialization of actor
  
  @param path    path of actor
  @param context context of actor
  @param mailbox mailbox of actor