public function moveLeftAction(Request $request)
    {
        $block = $this->findBlockByRequest($request);

        try {
            $sibling = $this->getEditor()->getBlockManager()->moveLeft($block);
        } catch (EditorExceptionInterface $e) {
            return $this->handleException($e);
        }

        $row = $block->getRow();

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

        $data = ['blocks' => [
            $this->getViewBuilder()->buildBlock($block),
            $this->getViewBuilder()->buildBlock($sibling),
        ]];

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