ProductFeed example

$feedId = $params['id'] ?? null;
        if (!empty($feedId)) {
            // Edit Product Feed             /** @var ProductFeed $productFeed */
            $productFeed = $this->get('models')->getRepository(ProductFeed::class)->find($feedId);
            // Clear all previous associations             $productFeed->getCategories()->clear();
            $productFeed->getSuppliers()->clear();
            $productFeed->getArticles()->clear();
        } else {
            // New Product Feed             $productFeed = new ProductFeed();
            // To set this value initial             $productFeed->setLastExport('now');
        }

        if (empty($params['shopId'])) {
            $params['shopId'] = null;
        }
        if (empty($params['categoryId'])) {
            $params['categoryId'] = null;
        }
        if (empty($params['customerGroupId'])) {