anchor.diff:  import 'upload_pack_parser.dart';
   
   final int COMMIT_LIMIT = 32;
  -
  -class RefPath {
  -  String name;
  -  String sha;
  -  String head;
  -
  -  RefPath(this.name, this.sha, this.head);
  -
  -  getPktLine() => '${sha} ${head} ${name}';
  -
  -  toString() => getPktLine();
  -}
   
   /**
    *
  
positive.code: 
    Future<List<GitRef>> fetchUploadRefs() => _fetchRefs('git-upload-pack');
  
    Future pushRefs(List<RefPath> refPaths, chrome.ArrayBuffer packData,
        progress) {
      Completer completer = new Completer();
      String url = _makeUri('/git-receive-pack', {});
      Blob body = _pushRequest(refPaths, packData);
      HttpRequest xhr = getNewHttpRequest();
      xhr.open("POST", url, async: true , user: username , password: password);
      xhr.onLoad.listen((event) {
  
negative.code:     }
  
      blobParts.add('0000');
      blobParts.add(new Uint8List.fromList(packData));
      return new Blob(blobParts);
    }
  
  