anchor.diff:      },
       'packagesToNotify': packagesToNotify,
       'authorsToNotify': authorsToNotify.toList()..sort(),
  +    'onlyDart2Packages': onlyDart2Packages,
     };
     final String json = new JsonEncoder.withIndent('  ').convert(report);
     if (argv['output'] != null) {
  
positive.code:         allowsDart2Count++;
          if (!allowsDartDev && !allowsDart1) {
            onlyDart2Count++;
          }
        }
        if (selectForNotification && allowsDartDev && !allowsDart2) {
  
negative.code:   final ArgParser parser = new ArgParser()
      ..addOption('output', help: 'The report output file (or stdout otherwise)')
      ..addOption('top',
          help: 'Select the top N popular package for notification')
      ..addOption('age', help: 'Maximum age of the latest update, in days.');
    final ArgResults argv = parser.parse(args);
    final top = int.tryParse(argv['top'] as String ?? '0') ?? 0;
    final age = int.tryParse(argv['age'] as String ?? '0') ?? 0;
  
    int totalCount = 0;
    int noConstraint = 0;
  