def network(self, network_id):
        """Returns :class:`Network` instance for ``network_id``

        :type  network_id: str
        :param network_id: This is the ID of the network.
            This can be found by visiting your class page
            on Piazza's web UI and grabbing it from
            https://piazza.com/class/{network_id}
        """
        self._ensure_authenticated()
        return Network(network_id, self._rpc_api.session)