protected function _authenticateQueryDql(\Doctrine\ORM\Query $dqlQuery)
    {
        try {
            $resultIdentities = $dqlQuery->getResult();
        } catch (\Exception $e) {
            throw new \Zend_Auth_Adapter_Exception('The supplied parameters to Extlib\Auth\Adapter\Doctrine2 failed to '
                . 'produce a valid sql statement, please check table and column names '
                . 'for validity.', 0, $e);
        }

        return $resultIdentities;
    }