SQLGlobal::__construct PHP Метод

    public function __construct(&$db = null)
    {
        $this->db =& $db;
        $this->dbclass = get_class($this->db);
    }

 /**
  * @param object $db
  */
 public function __construct(&$db = null)
 {
     parent::__construct($db);
     $this->option['engine'] = 'MyISAM';
 }