/**
     * @Route("/%eccube_admin_route%/data_migration4/config", name="data_migration4_admin_config")
     * @Template("@DataMigration4/admin/config.twig")
     */
    public function index(Request $request, Connection $em)
    {
        ini_set('memory_limit', '6G');
        set_time_limit(900);	// 15分

        $this->delivery_id = [];
        $this->stock = [];
        $this->shipping_id = [];
        $this->product_class_id = [];
        $this->order_item = [];
        $this->product_image = [];

        $form = $this->createForm(ConfigType::class);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
echo 'OK';
die;
            // logをオフにしてメモリを減らす
            $em->getConfiguration()->setSQLLogger(null);

            $formFile = $form['import_file']->getData();
            
            ...