public function clearExpiredPDO()
    {
        if ($this->Using !== 'PDO') {
            return false;
        }
        $PDO = $this->WorkingData->prepare(self::clearExpiredQuery);
        if ($PDO !== false && $PDO->execute(['time' => time()])) {
            return ($PDO->rowCount() > 0);
        }
        return false;
    }