Store the user session for a client.

        The only difference with the :func:`socketio.Server.save_session`
        method is that when the ``namespace`` argument is not given the
        namespace associated with the class is used.

def save_session(self, sid, session, namespace=None):
        """Store the user session for a client.

        The only difference with the :func:`socketio.Server.save_session`
        method is that when the ``namespace`` argument is not given the
        namespace associated with the class is used.
        """
        return self.server.save_session(
            sid, session, namespace=namespace or self.namespace)