public function onPostSerialize(ObjectEvent $event)
    {
        $document = $event->getObject();

        if (!($document instanceof SecurityBehavior
            && $document instanceof LocaleBehavior
            && $document instanceof WebspaceBehavior
            && null !== $this->tokenStorage
            && null !== $this->tokenStorage->getToken()
            && $this->tokenStorage->getToken()->getUser() instanceof UserInterface)
        ) {
            return;
        }

        /** @var JsonSerializationVisitor $visitor */
        $visitor = $event->getVisitor();

        $visitor->addData(
            '_permissions',
            $this->accessControlManager->getUserPermissionByArray(
                $document->getLocale(),
                PageAdmin::SECURITY_CONTEXT_PREFIX . $document->getWebspaceName(),
                $document->getPermissions(),
                $this->tokenStorage->getToken()->getUser()
            )
        );
    }