public function listContentTypesForGroup($contentTypeGroupId, Request $request)
    {
        $contentTypes = $this->contentTypeService->loadContentTypes(
            $this->contentTypeService->loadContentTypeGroup($contentTypeGroupId, Language::ALL),
            Language::ALL
        );

        if ($this->getMediaType($request) === 'application/vnd.ez.api.contenttypelist') {
            return new Values\ContentTypeList($contentTypes, $request->getPathInfo());
        }

        return new Values\ContentTypeInfoList($contentTypes, $request->getPathInfo());
    }