anchor.diff:               "metadata": {
                  "accuracy": {
                    "value": 2,
  -                 "type": "none"
  +                 "type": "Number"
                  },
                  "timestamp": {
                    "value": "2015-06-04T07:20:27.378Z",
  
positive.code:             "type": "Room",
              "attrs": {
                "pressure": {
                  "types": [ "none" ]
                },
                "humidity": {
                  "types": [ "percentage" ]
  
negative.code:             "metadata": {
                "providingService": {
                   "value": "weather.example.com",
                   "type": "Text"
                 },
                "providingAuthority": {
                   "value": "AEMET - Spain",
                   "type": "Text"
                 }
              },
              "duration": "PT1M"
  