public static function retrieve($params)
 {
     $paths = sfConfig::get("app_rest_doc_dir");
     foreach (self::array_values_recursive($paths) as $path) {
         if (!is_dir($path)) {
             continue;
         }
         $dir = dir($path);
         while (false !== ($file = $dir->read())) {
             if (!is_file($dir->path . "/{$file}")) {
                 continue;
             }
             try {
                 $service = new sfRestDocService();
                 $service->loadFromXml($dir->path . "/{$file}");
                 if ($service->getSlug() == $params['slug'] && $service->getRessourceSlug() == $params['ressourceSlug']) {
                     $dir->close();
                     return $service;
                 }
             } catch (Exception $e) {
                 sfContext::getInstance()->getLogger()->log("{$file} is not a valid REST Documentation file : " . $e->getMessage(), sfLogger::ALERT);
             }
         }
         $dir->close();
     }
 }