private function upgradeWebspace(Webspace $webspace)
    {
        $sessionManager = $this->container->get('sulu.phpcr.session');
        $node = $sessionManager->getContentNode($webspace->getKey());

        foreach ($webspace->getAllLocalizations() as $localization) {
            $locale = $localization->getLocale();
            $propertyName = $this->getPropertyName(self::SHADOW_ON_PROPERTY, $locale);

            $this->upgradeNode($node, $propertyName, $locale);
        }
    }