anchor.diff:  + Response 200 (application/hal+json)
   
       [ServiceUser][]
  -    
  +
   + Response 404 (application/vnd.error+json)
   
           {
  
positive.code:                                 "self": { "href": "/stages/6" }
                              },
                              "id": 6,
                              "name": "Gateway Protection Programme"
                          }
                      ]
                  },
                  "total": 6
              }   
              
  # Group Categories
  
  ## Category [/categories/{id}]
  
negative.code:                 "self": { "href": "/categories/1" }
              },
              "id": 1,
              "name": "Education",
              "position": 2
          }
  
  ### Read a Category [GET]
  + Response 200 (application/hal+json)
  
      [Category][]
  
  + Response 404 (application/vnd.error+json)
  
          {
  