public function onPreSerialize(ObjectEvent $event)
    {
        $configuredType = $event->getObject();

        if ($configuredType instanceof ConfiguredType) {
            try {
                $configurationArray = json_decode($configuredType->getConfiguration(), true);
                $extraFormType = $this->registry->getType($configurationArray['form_type']);
                $configuredType->setExtraFormType($extraFormType);
            } catch (\Exception $e) {
                return;
            }
        }
    }