anchor.diff:      _resourceName = resourceName;
       _resourceDetails = resourceDetails;
       _host = host;
  +    _provider = provider;
     }
   
     /// fromJson
  
positive.code:   }
  
    DartivityMessage.iHave(String source, String destination, String resourceName,
                           Map<String, dynamic> resourceDetails, String host) {
      if ((source == null) ||
      (resourceDetails == null) ||
      (destination == null) ||
      (resourceName == null) ||
      (host == null)) {
        throw new DartivityException(DartivityException.INVALID_IHAVE_MESSAGE);
      }
      _type = Type.iHave;
  
negative.code:       List<Type> types = Type.values;
        _type = jsonobj.containsKey('type') ? types[jsonobj.type] : Type.unknown;
        _host = jsonobj.containsKey('host') ? jsonobj.host : "";
        _provider =
        jsonobj.containsKey('provider') ? jsonobj.host : PROVIDER_UNKNOWN;
        _source = jsonobj.containsKey('source') ? jsonobj.source : "";
        _destination =
        jsonobj.containsKey('destination') ? jsonobj.destination : "";
  