private function sortSubscribers($eventName)
    {
        \krsort($this->subscribers[$eventName]);
        $this->sorted[$eventName] = array();
        foreach ($this->subscribers[$eventName] as $priority => $subscribers) {
            foreach ($subscribers as $k => $subscriber) {
                if ($this->isClosureFactory($subscriber)) {
                    $subscriber[0] = $subscriber[0]();
                    $this->subscribers[$eventName][$priority][$k] = $subscriber;
                }
                $this->sorted[$eventName][] = $subscriber;
            }
        }
    }