code: def _do_server_auth(conn, auth_secret):
      
      write_with_length(auth_secret.encode("utf-8"), conn)
      conn.flush()
      reply = UTF8Deserializer().loads(conn)
      if reply != "ok":
          conn.close()
          raise Exception("Unexpected reply from iterator server.")
docs: Performs the authentication protocol defined by the SocketAuthHelper class on the given
      file-like object 'conn'.