anchor.diff:              {
                   "id": "abcdefg",
                   "subject": {
  -                    "entity": "Bcn_Welt",
  +                    "id": "Bcn_Welt",
                       "type": "Room",
  -                    "attributes": [
  -                        "temperature"
  -                    ],
  -                    "condition": "ONCHANGE"
  +                    "condition": {
  +                       "attrs:" [ "temperature " ],
  +                       "expression:" {
  +                          "q": "tempature>40"
  +                       }
  +                    }
                   },
                   "notification": {
                       "callback": "http://localhost:1234",
                       "attributes": ["temperature", "humidity"],
                       "throttling": "PT5S"
                   },
  -                "options": {
  -                    "duration": "PT1M"
  -                }
  +                "duration": "PT1M"
               }
           ]
   
  
positive.code:                 ]
              },
              "callback":  "http://localhost:1234",
              "options": {
                  "duration": "PT1M"
              }
          }
  
  + Response 201
  
negative.code: 
  ### updateContext [POST /v2/updateContext]
  
  The payload is an object which two properties:
  
  * `action`, to specify the kind of updateContext action to do (see OMA NGSI specification for the semantics), either UPDATE, APPEND or DELETE
  * `entities`, an array of entities, each one specified using the the JSON entity representation format (described in a section above).
  
  Response:
  
  * Successful operation uses 201 Created.
  * Errors use a non-200 and (optionally) an error payload. See subsection on Error Responses for more detail.
  
  + Request (application/json)
  
          {
              "action": "APPEND",
              "entities": [
                  {
                      "type": "Room",
                      "id": "Bcn-Welt",
                      "temperature": 21.7,
                      "humidity": 60
                  },
                  {
                      "type": "Room",
                      "id": "Mad_Aud",
                      "temperature": 22.9,
                      "humidity": 85
                  }
              ]
          }
  
  + Response 201
  
      + Headers
  
              Location: /v2/entities/Bcn-Welt
  
  ### subscribeContext [POST /v2/subscribeContext]
  
  ### updateContextSubscription [POST /v2/updateContextSubscription]
  