public function actionPreview($blockId)
    {
        $blockItem = Block::findOne($blockId);
        if (!$blockItem) {
            throw new NotFoundHttpException();
        }

        /** @var $blockObject \luya\cms\base\InternalBaseBlock */
        $blockObject = $blockItem->getObject('preview', 'admin-preview');

        return $blockObject->renderAdminPreview();
    }