### add 1 sku to cart
POST http://localhost:8080/user/31337/cart/1076963
Content-Type: application/json

{
  "count": 1
}
### expected {} 200 OK; must add 1 item

### add 5 sku to cart
POST http://localhost:8080/user/31337/cart/1076963
Content-Type: application/json

{
  "count": 5
}
### expected {} 200 OK; must add 5 more item, 1076963 - must be 6 items

### add unknown sku to cart
POST http://localhost:8080/user/31337/cart/1076963000
Content-Type: application/json

{
  "count": 1
}
### expected {} 412 Precondition Failed; invalid sku

### add another sku to cart
POST http://localhost:8080/user/31337/cart/1148162
Content-Type: application/json

{
  "count": 1
}
### expected {} 200 OK; must add 1 item

### invalid user
POST http://localhost:8080/user/0/cart/1148162
Content-Type: application/json

{
  "count": 1
}
### expected {} 400 Bad Request

### invalid sku
POST http://localhost:8080/user/31337/cart/0
Content-Type: application/json

{
  "count": 1
}
### expected {} 400 Bad Request

### invalid count
POST http://localhost:8080/user/31337/cart/1148162
Content-Type: application/json

{
  "count": 0
}
### expected {} 400 Bad Request

# ========================================================================================

### delete whole sku from cart
DELETE http://localhost:8080/user/31337/cart/1076963
Content-Type: application/json
### expected {} 204 No Content; must delete item from cart

### delete whole cart
DELETE http://localhost:8080/user/31337/cart
Content-Type: application/json
### expected {} 204 No Content; must delete cart

# ========================================================================================

### get list of a cart
GET http://localhost:8080/user/31337/cart
Content-Type: application/json
### expected {} 200 OK; must show cart

### get invalid list of cart
GET http://localhost:8080/user/0/cart
Content-Type: application/json
### 400 bad request