anchor.diff:      if (null != reason) {
         _me.displayWhenEmpty = reason;
         _user = null;
  -    } else {
  +    } else
         _user = new CodeWarsUser.fromJson(json);
  -    }
     }
   
     _performChangeCompleted(String _json) {
  
positive.code:     SharedPreferences.getInstance().then((sp) {
        setState(() {
          _performChangeUser(sp.getString(DatabaseKeys.USER) ??
              CodeWarsAPI.getErrorWithReason("not set"));
        });
      });
  
negative.code:     if (null != reason) {
        _kata.displayWhenEmpty = reason;
        _completed = null;
      } else
        _completed = KataCompleted.fromJson(json);
    }
  
    @override
  