            $retVal = preg_replace_callback ($pattern, $callback, $subject, $limit);
        } else {
            $retVal = preg_replace_callback ($pattern, $callback, $subject);
        }
        if ($throws && $retVal === null) {
            throw new StringUtilException (
                Yii::t('app', 'preg_replace_callback error: '.
                    StringUtilException::getErrorMessage (preg_last_error ())), 
                StringUtilException::PREG_REPLACE_CALLBACK_ERROR);
        }
        return $retVal;
    }
The product receives input or data, but it does
        not validate or incorrectly validates that the input has the
        properties that are required to process the data safely and
        correctly.