def my_pick_non_system_keyspace(self):
        d = self.my_describe_keyspaces()

        def pick_non_system(klist):
            for k in klist:
                if k.name not in SYSTEM_KEYSPACES:
                    return k.name
            err = NoKeyspacesAvailable("Can't gather information about the "
                                       "Cassandra ring; no non-system "
                                       "keyspaces available")
            warn(err)
            raise err
        d.addCallback(pick_non_system)
        return d
Find a keyspace in the cluster which is not 'system', for the purpose
dataset/ETHPy150Open driftx/Telephus/telephus/pool.py/CassandraPoolReconnectorFactory.my_pick_non_system_keyspace