anchor.diff:        for (var label in toRemove) clusters.remove(label);
       }
   
  +    if (opts.labels && opts.skipUninteresting) {
  +      Set<String> toRemove = Set<String>();
  +      for (var label in clusters.clusters.keys) {
  +        if (labelsToSkip.contains(label)) toRemove.add(label);
  +      }
  +      for (var label in toRemove) clusters.remove(label);
  +    }
  +
       print(clusters.toMarkdown(
           sortType: (opts.alphabetize
               ? ClusterReportSort.byKey
  
positive.code:   bool get issues => _results['issues'];
    bool get alphabetize => _results['alphabetize'];
    bool get customers => _results['customers-only'];
    int get exitCode => _results == null ? -1 : _results['help'] ? 0 : null;
  
    Options(List<String> args) {
  
negative.code: 
    void _printUsage() {
      print(
          'Usage: pub run clusters.dart [--labels] [--skip-uninteresting-labels] [--authors] [--assignees] [--prs] [--issues] [--merged fromDate toDate] [--closed fromDate toDate]');
      print('Prints PRs in flutter/flutter, flutter/engine repositories.');
      print('  Dates are in ISO 8601 format');
      print('  --merged and --closed are mutally exclusive');
  