protected function configureStatementClass($class = 'PDOStatement', $suppressError = true)
    {
        // extending PDOStatement is only supported with non-persistent connections
        if (!$this->getAttribute(PDO::ATTR_PERSISTENT)) {
            $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array($class, array($this)));
        } elseif (!$suppressError) {
            throw new PropelException('Extending PDOStatement is not supported with persistent connections.');
        }
    }