public function deleteHandler($event, $handler)
    {
        if (empty($event)) {
            throw new \Exception("Event is not specified!");
        }
        
        if (!is_callable($handler)) {
            throw new \Exception("Event handler is not valid!");
        }
        
        try {
            $f = new \ReflectionFunction($handler);
        } catch (\Exception $ex) {
            throw new \Exception($ex->getMessage());
        }
        
        if (isset(self::$event_table[$event][$f->__toString()])) {
            unset(self::$event_table[$event][$f->__toString()]);
        }
        
        return true;
    }