public function handleRemove(RemoveEvent $event)
    {
        $document = $event->getDocument();
        if (!($document instanceof CustomUrlBehavior)) {
            return;
        }

        foreach ($this->inspector->getReferrers($document) as $referrer) {
            if ($referrer instanceof RouteBehavior) {
                $this->documentManager->remove($referrer);
            }
        }
    }