anchor.diff:  }
   
   class PostItem {
  -  PostItem({this.urlPath});
  +  final String title;
     final String urlPath;
  -}
  +
  +  PostItem({this.title, this.urlPath});
  +}
  
positive.code:     final PostItem item = _postItemForMessage(message);
      // Clear away dialogs
      Navigator.popUntil(context, (Route<dynamic> route) => route is PageRoute);
      Navigator.push(
          context,
          new MaterialPageRoute(
            builder: (context) => new PostPage(item.urlPath),
          ));
    }
  
    PostItem _postItemForMessage(Map<String, dynamic> message) {
      final String urlPath = Uri.parse(message['url']).path;
      return new PostItem(urlPath: urlPath);
    }
  
    void _showPostItemDialog(Map<String, dynamic> message) {
  
negative.code:         Navigator.push(
              context,
              new MaterialPageRoute(
                builder: (context) => new PostPage(model, widget.favoriteList,
                    widget.onFavoriteAdded, widget.onFavoriteRemoved),
              ));
        },
      );
  