anchor.diff:      }, cancelOnError: cancelOnError);
       _subscriptions.add(subscription);
     }
  -
  -  /// Return a human-friendly string representation of [event].
  -  String _formatEvent(FileSystemEvent event) {
  -    if (event == null) return 'null';
  -
  -    var path = p.relative(event.path, from: directory);
  -    var type = event.isDirectory ? 'directory' : 'file';
  -    if (event is FileSystemCreateEvent) {
  -      return "create $type $path";
  -    } else if (event is FileSystemDeleteEvent) {
  -      return "delete $type $path";
  -    } else if (event is FileSystemModifyEvent) {
  -      return "modify $type $path";
  -    } else if (event is FileSystemMoveEvent) {
  -      return "move $type $path to "
  -          "${p.relative(event.destination, from: directory)}";
  -    }
  -  }
  -
  -  // TODO(nweiz): remove this when the buildbots calm down.
  -  /// Whether this code is running on a buildbot.
  -  bool get _runningOnBuildbot =>
  -    Platform.environment['LOGNAME'] == 'chrome-bot';
   }
  
positive.code:     // probably comes from FSEvents reporting an add that happened prior to the
      // watch beginning.
      if (type == ChangeType.ADD && _files.contains(path)) return;
  
      if (_runningOnBuildbot) {
        print("emitting $type ${p.relative(path, from: directory)}");
      }
  
      _eventsController.add(new WatchEvent(type, path));
    }
  
negative.code:       if (entity is! Directory) _files.add(entity.path);
      },
          onError: _emitError,
          onDone: _readyCompleter.complete,
          cancelOnError: true);
    }
  
  