originals = {row['id']: row for row in data['products']}
check('未增加库存、材质或商品编码', all(row['stock'] == originals[row['id']]['stock'] and row['material'] == originals[row['id']]['material'] and row['gtin'] in {originals[row['id']]['gtin'], None} for row in output['products']))
save_csv(folder / 'feed.csv', output['products'])
