(Quick Reference)
                Service: Show an item-unit
Description: Returns the requested item-unit in json format when successful. Returns a json response, describing the failure condition when unsuccessful.
Method: GET
URL: 
https://BASE_URL/api/VERSION/itemUnits/{id}:
| Name | Description | Type | Required | Example values | 
|---|
| id | The numerical ID of the desired item unit | Long | Yes | 777 | 
URL with external_id: 
https://BASE_URL/api/VERSION/itemUnits/reference/{itemId}/{unitId}:
| Name | Description | Type | Required | Examples values | 
|---|
| itemId | reference of the item | String | Yes | eliteBook_820 | 
| unitId | reference of the unit | String | Yes | Piéce | 
Success Output
 Success case: response.status = 200 
{
  "id": 1,
  "itemReference": "bracelet-GRP09062",
  "unitReference": "pcs",
  "item": {
    "id": 497,
    "reference": "bracelet-GRP09062",
    "name": "Knot Band Bracelet",
    "href": "/api/v1.0/items/497"
  },
  "unit": {
    "id": 1,
    "reference": "pcs",
    "name": "pieces",
    "href": "/api/v1.0/units/1"
  },
  "quantity": 1,
  "unpacking": true,
  "salesQuantity": 4,
  "volume" : 5,
  "weight" : 15.33,
  "barcode": "(10)45566(17)161231",
  "expirationDate": "2016-12-31",
  "isDefault": true,
  "defaultDisplay": true,
  "organization": "entity1",
  "dateCreated": "2015-12-17T08:17:07Z",
  "lastUpdated": "2016-01-08T08:10:54Z"
} Failure Output
 Failure case:response.status = 400 
{
    "error": "invalid_param_type",
    "error_description": "The type of parameter id you provided is not valid for this request."
} Failure case:response.status = 404 
{
  "error": "not_found",
  "error_description": "The item unit with the id 1000 doesn't exist."
}