public function __construct($id = null)
 {
     if (!MULTIPROVIDER && isset($GLOBALS['user_provider']) && !empty($GLOBALS['user_provider'])) {
         $dsn = MultiPort::getDSN($GLOBALS['user_provider']);
     } else {
         $dsn = null;
     }
     $this->dataHandler = AMALoginDataHandler::instance($dsn);
     if (is_null($id)) {
         $id = $this->dataHandler->getLoginProviderIDFromClassName(get_class($this));
     }
     $this->id = intval($id);
 }