public function deleteContentTypeGroup($contentTypeGroupId) { $contentTypeGroup = $this->contentTypeService->loadContentTypeGroup($contentTypeGroupId); $contentTypes = $this->contentTypeService->loadContentTypes($contentTypeGroup); if (!empty($contentTypes)) { throw new ForbiddenException('Only empty content type groups can be deleted'); } $this->contentTypeService->deleteContentTypeGroup($contentTypeGroup); return new Values\NoContent(); }