anchor.diff:      tagList.remove(uuid, postList);
   
       tagList.dump()
  -    .then((_) {
  -      completer.complete(true);
  -    })
  +    .then((_) => completer.complete(true))
       .catchError((e, trace) {
         PinUtility.handleError(e, trace);
         completer.completeError(e, trace);
  
positive.code:       }
        return new Future.value(true);
      })
      .then((_) {
        // update or create local html file
        return (new File(LibPath.join(postBaseDataDir, post.uuid + '.html'))).writeAsString(html);
      })
      .then((_) {
        // upload attachments
        post.attachments.forEach((String attachmentUuid, CartPostAttachment attachment) {
  
negative.code:       post = _;
        return _postUpload(post, markdown);
      })
      .then((CartPost _) => saveDatabase())
      .then((_) => completer.complete(post.generateHeaderInfo()))
      .catchError((e, trace) {
        PinUtility.handleError(e, trace);
        completer.completeError(e, trace);
  