anchor.diff:  A `subject` contains the following subfields:
   
   + `entities`: A list of objects, each one composed of the following subfields (`id`/`idPattern` or `type` must be present):
  -    + `id` or `idPattern`: Id or pattern of the affected entities (optional). Both cannot be used at the same time.
  +    + `id` or `idPattern`: Id or pattern of the affected entities. Both cannot be used at the same time, but at least one of them must be set.
       + `type`: Type of the affected entities (optional).
   + `condition`: Condition that will trigger the notification. It can have two optional properties:
       + `attributes`: array of attribute names
  
positive.code:          {
              "type": "Room",
              "id": "DC_S1-D41",
              "temperature": {
                "value": 35.6,
                "type": "none"
              }
           },
           {
              "type": "Room",
              "id": "Boe-Idearium",
              "temperature": {
                "value": 22.5,
                "type": "none"
              }
           },
           {
              "type": "Car",
  
negative.code:             "description": "One subscription to rule them all",
              "subject": {
                  "entities": [
                          "idPattern": ".*",
                          "type": "Room"
                      }
                  ],
  