protected function _getConfigParamsSelectSnippet($vars)
    {
        $select = '';
        if (is_array($vars) && !empty($vars)) {
            foreach ($vars as &$field) {
                $field = '"' . $field . '"';
            }
            $select = ' and oxvarname in ( ' . implode(', ', $vars) . ' ) ';
        }

        return $select;
    }