anchor.diff:  
           {
             "id": "abcde",
  -          "subject": {
  +          "dataProvided": {
               "entities": [
                 {
                   "id": "room2",
  
positive.code:                 "temperature"
                ]
              },
              "callback": "http://weather.example.com/ngsi",
              "metadata": {
                "providingService": {
                   "value": "weather.example.com",
                   "type": "Text"
                 },
                "providingAuthority": {
                   "value": "AEMET - Spain",
                   "type": "Text"
                 }
              },
              "duration": "PT1M"
            }
          ]
  
  ### Create a new context provider registration [POST /v2/registrations]
  
  Creates a new registration. This is typically used for associating context providers
  to certain data.
  The registration is represented by a JSON object as described at the beginning of this section.
  
  
negative.code:         [
            {
              "id": "abcdefg",
              "dataProvided": {
                "entities": [
                  {
                    "id": "Bcn_Welt",
  