anchor.diff:  import 'dart:io';
   import 'dart:mirrors';
   
  +import 'package:dart_style/src/dart_formatter.dart';
   import 'package:path/path.dart' as p;
   import 'package:test/test.dart';
   
  
positive.code:   var input = getFile(dartFileName, summaryExtension);
    var golden = getFile(dartFileName, goldenExtension);
  
    expect(await input.readAsString(), await golden.readAsString());
  }
  
  File getFile(String dartFileName, String extension) =>
  
negative.code: 
  String _scriptDir() =>
      p.dirname(currentMirrorSystem().findLibrary(#compare_to_golden).uri.path);
  
  final _formatter = new DartFormatter();
  