(Quick Reference)
                Service: Update
Description: This web service is used to update an existing assigned item group object to the database
Method: PUT
Request content type: application/json
URL: 
https://BASE_URL/api/VERSION/itemCustomerGroup/{id} Parameters:
| Name | Description | Type | Required | Example values | 
|---|
| id | id of the desired assigned item customer group to update | Long | Yes | 111 | 
| customerGroupId | the id of the customer group to be assigned | Long | Yes | 777 | 
| itemId | the id of the new item to assign to customerGroup | Long | Yes | 123 | 
URL with external_id: 
https://BASE_URL/api/VERSION/itemCustomerGroup/reference/{itemId}/{customerGroupId} Parameters:
| Name | Description | Type | Required | Examples values | 
|---|
| itemId | reference of the item | String | Yes | I-002 | 
| customerGroupId | reference of the customer group | String | Yes | IG-001 | 
Success Output
 Success case: response.status=200 
{
    "id": 159,
    "itemReference": "R-A-001",
    "customerGroupReference": "RG-3",
    "item": {
      "id": 1751,
      "reference": "R-A-001",
      "name": "article1",
      "href": "/api/v1.0/items/1751"
    },
    "customerGroup": {
      "id": 23,
      "reference": "RG-3",
      "name": "new CustomerGroup3",
      "href": "/api/v1.0/customerGroups/23"
    },
    "organization": "Lyon",
    "dateCreated": "2016-08-23T11:23:27Z",
    "lastUpdated": "2016-08-23T11:23:27Z"
} 
 Failure Output
 Failure case:response.status = 400 
{
    "error": "missing_param",
    "error_description": "customerGroupId parameter is missing"
} 
{
    "error": "already_assigned",
    "error_description": "item is already assigned to customerGroup."
} 
{
    "error": "invalid_param_type",
    "error_description": "The type of parameter id you provided is not valid for this request."
} 
{
     "error": "save_failed",
     "error_description": "Failed to save instance"
} Failure case:response.status = 404 
{
    "error": "not_found",
    "error_description": "The customer group with the id 999 doesn't exist."
} Failure case:response.status = 500 
{
    "error": "server_error",
    "error_description": "Oops! Something went wrong..."
}