anchor.diff:  
     Options(List<String> args) {
       _parser
  -      ..addFlag('help', defaultsTo: false, abbr: 'h', negatable: false, help: 'get usage')
  -      ..addFlag('closed', defaultsTo: false, abbr: 'c', negatable: false, help: 'show punted issues in date range')
  -      ..addFlag('merged', defaultsTo: false, abbr: 'm', negatable: false, help: 'show merged PRs in date range');
  +      ..addFlag('help',
  +          defaultsTo: false, abbr: 'h', negatable: false, help: 'get usage')
  +      ..addFlag('closed',
  +          defaultsTo: false,
  +          abbr: 'c',
  +          negatable: false,
  +          help: 'show punted issues in date range')
  +      ..addFlag('merged',
  +          defaultsTo: false,
  +          abbr: 'm',
  +          negatable: false,
  +          help: 'show merged PRs in date range');
       try {
         _results = _parser.parse(args);
  -      if (_results['help'])  _printUsage();
  -      if ((_results['closed'] || _results['merged']) && _results.rest.length != 2 ) throw('need start and end dates!');
  -      if (_results['merged'] && _results['closed']) throw('--merged and --closed are mutually exclusive!');
  +      if (_results['help']) _printUsage();
  +      if ((_results['closed'] || _results['merged']) &&
  +          _results.rest.length != 2) throw ('need start and end dates!');
  +      if (_results['merged'] && _results['closed'])
  +        throw ('--merged and --closed are mutually exclusive!');
       } on ArgParserException catch (e) {
         print(e.message);
         _printUsage();
  
positive.code: 
    var nonGoogleContributions = List<PullRequest>();
    int processed = 0;
    for(var item in prs) {
      var pullRequest = item as PullRequest;
      processed++;
        if (!googleContributors.contains(pullRequest.author.login)) {
          nonGoogleContributions.add(pullRequest);
          continue;
        }
        if (pullRequest.assignees != null) {
          for(var assignee in pullRequest.assignees) {
            if (!googleContributors.contains(assignee.login)) {
              nonGoogleContributions.add(pullRequest);
              break;
            }
          }
      }
    }
  
  
    var clustersInterestingOwned = Cluster.byAuthor(nonGoogleContributions);
    print(clustersInterestingOwned.toMarkdown(sortType: ClusterReportSort.byCount, skipEmpty: true, showStatistics: false));
  }
negative.code: 
    void _printUsage() {
      print('Usage: pub notable-contributors.dart [-closed fromDate toDate]');
      print(
          'Prints non-Google contributors by contributor cluster in the specified date range');
      print('  Dates are in ISO 8601 format');
      print(_parser.usage);
    }
  