anchor.diff:  
   import 'dart:async';
   import 'dart:io';
  +
  +import 'package:path/path.dart' as p;
   
   import '../constructable_file_system_event.dart';
   import '../path_set.dart';
  
positive.code:             if (entity is Directory) return;
              _emitEvent(ChangeType.ADD, entity.path);
              _files.add(entity.path);
            }, onError: _emitError, cancelOnError: true);
          } else if (event is FileSystemModifyEvent) {
            assert(!event.isDirectory);
            _emitEvent(ChangeType.MODIFY, path);
  
negative.code:     var fileExists = new File(path).existsSync();
      var dirExists = new Directory(path).existsSync();
  
      if (_runningOnBuildbot) {
        print("file existed: $fileExisted");
        print("dir existed: $dirExisted");
        print("file exists: $fileExists");
        print("dir exists: $dirExists");
      }
  
      var events = [];
      if (fileExisted) {
        if (fileExists) {
  