anchor.diff:    DateTime get from => DateTime.parse(_results['from']);
     DateTime get to => DateTime.parse(_results['to']);
     int get exitCode => _results == null ? -1 : _results['help'] ? 0 : null;
  -  bool get excludePerformance => _results['include-performance'] ?? false;
  +  bool get excludePerformance => _results['exclude-performance'] ?? false;
     Options(List<String> args) {
       _parser
         ..addFlag('help',
  
positive.code:     labels: ['severe: performance'],
    );
  
    var closedPerfIssues = await github.search(
      owner: 'flutter',
      name: 'flutter',
      type: GitHubIssueType.issue,
  
negative.code:           defaultsTo: DateTime.now().toIso8601String(),
            abbr: 't',
            help: 'to date, ISO format yyyy-mm-dd')
        ..addOption('exclude-performance',
            abbr: 'e', help: 'include performance issues');
      try {
        _results = _parser.parse(args);
        if (_results['help']) _printUsage();
  