anchor.diff:    var parser = new ArgParser();
     parser.addOption('in',    abbr: 'i');
     parser.addOption('out',   abbr: 'o');
  -  parser.addOption('group', abbr: 'g');
  -  parser.addOption('gs');
  +  parser.addOption('group', abbr: 'g', allowMultiple: true);
   
     var argResults = parser.parse(args);
   
  
positive.code:     } else {
        exportFile = new File(argResults['out']);
      }
      exportFile.writeAsStringSync(csv);
      print('');
      print('complete!');
    });
  
  }
  
negative.code: 
    Future<String> csvResult;
  
    if(argResults['group'].length == 0) {
      csvResult = searchAll();
    } else {
  
      List<FileSystemEntity> targetFs = new List();
      argResults['group'].forEach((String path) =>
        targetFs.addAll(parseDirectory(path.replaceFirst(new RegExp(r'\/$'), ''), rootDir.path))
      );
      print(targetFs);
  
      csvResult = searchGroups(targetFs);
  