public function moveDownAction(Request $request)
    {
        $container = $this->findContainerByRequest($request);

        try {
            $sibling = $this->getEditor()->getContainerManager()->moveDown($container);
        } catch (EditorExceptionInterface $e) {
            return $this->handleException($e);
        }

        $content = $container->getContent();

        $this->validate($content);
        $this->persist($content);

        $data = [
            'containers' => [
                $this->getViewBuilder()->buildContainer($container),
                $this->getViewBuilder()->buildContainer($sibling),
            ],
        ];

        return $this->buildResponse($data, self::SERIALIZE_LAYOUT);
    }