protected function _addMessageToBuffer(Rediska_PubSub_Response_Message $message)
    {
        $key = "{$message->getConnection()->getAlias()}-{$message->getChannel()}";

        if (!isset(self::$_messages[$key])) {
            self::$_messages[$key] = array();
        }

        self::$_messages[$key][] = $message;
    }