def __init__(self, **kwargs):
        super(Session, self).__init__(**kwargs)
        self._check_packers()
        self.none = self.pack({})
        # ensure self._session_default() if necessary, so bsession is defined:
        self.session
        self.pid = os.getpid()
        self._new_auth()
        if not self.key:
            get_logger().warning("Message signing is disabled.  This is insecure and not recommended!")
create a Session object
dataset/ETHPy150Open jupyter/jupyter_client/jupyter_client/session.py/Session.__init__