anchor.diff:      exit(0);
     }
     var allMessages = {};
  +  if (locale != null) {
  +    allMessages["@@locale"] = locale;
  +  }
     for (var arg in args.where((x) => x.contains(".dart"))) {
       var messages = extraction.parseFile(new File(arg), transformer);
       messages.forEach((k, v) => allMessages.addAll(toARB(v)));
  
positive.code:   bool transformer;
    var parser = new ArgParser();
    var extraction = new MessageExtraction();
    parser.addFlag("suppress-warnings",
        defaultsTo: false,
        callback: (x) => extraction.suppressWarnings = x,
  
negative.code:       help: "Assume that the transformer is in use, so name and args "
            "don't need to be specified for messages.");
  
    parser.addOption("locale",
        defaultsTo: null,
        callback: (value) => locale = value,
        help: 'Specify the locale set inside the arb file.');
    parser.addOption("output-dir",
        defaultsTo: '.',
        callback: (value) => targetDir = value,
  