code: def configsvrs(self):
          
          if self.uses_rs_configdb:
              rs_id = self._configsvrs[0]
              mongodb_uri = ReplicaSets().info(rs_id)['mongodb_uri']
              return [{'id': rs_id, 'mongodb_uri': mongodb_uri}]
          return [{'id': h_id, 'hostname': Servers().hostname(h_id)}
                  for h_id in self._configsvrs]
docs: return list of config servers