anchor.diff:   * A loose git object.
    */
   class LooseObject {
  -  int _size;
  -  String _type;
  +  int size;
  +  int type;
  +
  +  static Map<String, int> _typeMap = {
  +    ObjectTypes.COMMIT : 1,
  +    ObjectTypes.TREE : 2,
  +    ObjectTypes.BLOB : 3
  +  };
   
     // Represents either an ArrayBuffer or a string representation of byte
     //stream.
  
positive.code:         return new BlobObject(sha, content);
        case ObjectTypes.TREE:
        case "Tree":
          return new TreeObject(sha, content);
        case ObjectTypes.COMMIT:
          return new CommitObject(sha, content, rawObj);
        case ObjectTypes.TAG:
  
negative.code: class TreeObject extends GitObject {
  
    List<TreeEntry> entries;
    LooseObject rawObj;
  
    TreeObject( [String sha, Uint8List data, LooseObject rawObj])
        : super(sha, data) {
      this._type = ObjectTypes.TREE;
      this.rawObj  = rawObj;
      _parse();
    }
  
  