public function listAction($context = null)
    {
        return new JsonResponse([
            'widgets' => array_map(function (Widget $widget) {
                return $this->serializer->serialize($widget);
            }, $this->widgetManager->getAvailable($context)),
            'dataSources' => array_map(function (DataSource $dataSource) {
                return $this->serializer->serialize($dataSource);
            }, $this->dataSourceManager->getAvailable($context)),
        ]);
    }