def get_group_stats(self, dpid, group_id=None):
        url = (self._of_base_url +
               'stats/groups?dpid={0}'.format(urllib.quote(dpid)))
        if group_id:
            url = url + '&group_id={0}'.format(group_id)
        return self.restclient.get(url)
List group statistics
dataset/ETHPy150Open dave-tucker/hp-sdn-client/hpsdnclient/of.py/OfMixin.get_group_stats