anchor.diff:  import 'package:_fe_analyzer_shared/src/scanner/io.dart'
       show readBytesFromFileSync;
   import 'package:_fe_analyzer_shared/src/scanner/scanner.dart';
  +import 'package:args/args.dart';
   import 'package:front_end/src/api_prototype/front_end.dart';
   import 'package:front_end/src/api_prototype/language_version.dart';
   import 'package:front_end/src/api_prototype/terminal_color_support.dart'
  
positive.code: import 'package:vm/target/vm.dart' show VmTarget;
  
  void main(List<String> args) async {
    var prefix = args.isEmpty ? 'pkg/compiler/' : args.first;
    var files = <Uri, List<int>>{};
    var isLegacy = <Uri>{};
    var isNullSafe = <Uri>{};
  
negative.code:   final int migratedDependencies;
  
    double get ratio => migratedDependencies / totalDependencies;
  
    FileData(this.isNullSafe, this.totalDependencies, this.migratedDependencies);
  }
  
  