code: def ts_stream_keys(self, table, timeout=None):
          
          msg_code = riak.pb.messages.MSG_CODE_TS_LIST_KEYS_REQ
          codec = self._get_codec(msg_code)
          msg = codec.encode_timeseries_listkeysreq(table, timeout)
          self._send_msg(msg.msg_code, msg.data)
          return PbufTsKeyStream(self, codec, self._ts_convert_timestamp)
docs: Streams keys from a timeseries table, returning an iterator that
          yields lists of keys.