gistfile1.txt

Поменял количество товара с 1 на 4, в ответ "We're sorry, but something went wrong (500)"
[
  {
    "changing_state" : "changed",
    "id" : "534ce9ea61646d7c8d020000",
    "total_price" : {
      "cents" : 0,
      "currency" : "RUB"
    },
    "updated_at" : 1397550435,
    "items" : [
      {
        "product_id" : 1202329,
        "price" : {
          "cents" : 0,
          "currency" : null
        },
        "products_list_id" : "534ce9ea61646d7c8d020000",
        "changing_state" : "changed",
        "id" : "534cea0861646d7dbd000000",
        "updated_at" : 1397550425,
        "version" : 0,
        "stricken" : 0,
        "count" : 4,
        "title" : "Тачка садовая FIT, 65 л"
      }
    ],
    "version" : 0,
    "items_count" : 2,
    "title" : "23"
  }
]