anchor.diff:    Map _userMap;
   
     PreferenceStore _persistentStore;
  -  Future<bool> whenLoaded;
  +  Future whenLoaded;
     bool _loaded = false;
   
     // TODO: implement isDirty
     bool get isDirty => null;
  -
  -  bool _firstRun = false;
  -  bool get firstRun => _firstRun;
   
     Stream<PreferenceEvent> get onPreferenceChange => _changeConroller.stream;
     StreamController<PreferenceEvent> _changeConroller = new StreamController();
  
positive.code:   }
  
    Future _loadUserPrefs() {
      return _persistentStore.getValue("userJsonPrefs", "")
          .then((String json) {
        if (json == "") {
          _firstRun = true;
          json = "{}";
        }
        _userMap = JSON.decode(json);
      });
    }
  
negative.code:     editorFontSize = new JsonPreference<num>(_jsonStore, "editorFontSize");
      keyBindings = new JsonPreference<String>(_jsonStore, "keyBindings");
  
      onPreferencesReady = _jsonStore.whenLoaded;
    }
  }
  
  