anchor.diff:              }
   
   ### Retrieve a List of Subjects [GET]
  -Subjects allow a special sort option called 'random' that produces a
  -random list of subjects that have not been seen by the
  -active user. When the random sort is used, *workflow_id* is a
  -required parameter.
  +Subjects allow a special sort option called 'cellect' that produces a
  +list of subjects that have not been seen by the active user.
  +When the cellect sort is used, *workflow_id* is a required parameter.
   
   Subjects also allow an 'queued' sort, which will return a random
   subset of subjects have a been queued for a particular user to
  
positive.code:   + per_page (optional, integer) ... number of items per page 20 by default
    + sort (optional, string) ... field to sort by, id by default
    + user_id (optional, integer) ... filter list to groups a user is part of
  
  + Response 200
  
  
negative.code: 
  + Model (application/vnd.api+json)
  
      + Body
  
              {
                  "links": {
                      "users.projects": {
                          "href": "/projects?user_id={users.id}",
                          "type": "projects"
                      },
                      "users.user_groups": {
                          "href": "/groups?user_id={users.id}",
                          "type": "user_groups"
                      },
                      "users.subjects": {
                          "href": "/subjects?user_id={users.users.id}",
                          "type": "subjects"
                      },
                      "users.collections": {
                          "href": "/collections?user_id={users.id}",
                          "type": "collections"
                      }
                  },
                  "users": [{
                      "id": 1,
                      "created_at": "2014-03-20T00:15:47Z",
                      "updated_at": "2013-09-30T10:20:32Z",
                      "credited_name": "Dr. Stuart Lynn",
                      "display_name": "stuart",
                      "login": "stuart",
                      "email": "stuart@zoooniverse.org",
                      "zooniverse_id": "123432",
                      "classifications_count": "104",
                      "langauges": ["en-gb", "es-mx"]
                  }]
              }
  
  ### Retrieve a single User [GET]
  The *email* attribute is only available if the requesting user is an
  administrator or the user resource being requested is that of the
  requesting user.
  
  + Response 200
  
      [User][]
  