Return the rooms a client is in.

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

def rooms(self, sid, namespace=None):
        """Return the rooms a client is in.

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