anchor.diff:  import 'package:args/args.dart';
   import 'package:http/http.dart' as http;
   
  -void usage(ArgParser parser) {
  +void usage(ArgParser parser, {exitCode = 0}) {
     print('''
   Usage: post_results_to_pubsub.dart [OPTIONS]
   Posts Dart CI results as messages to Google Cloud Pub/Sub
  
positive.code:     print('No results in input file');
      return;
    }
  
    final changedPattern = '"changed":true';
    List<String> changedResults =
  
negative.code: The options are as follows:
  
  ${parser.usage}''');
    exit(exitCode);
  }
  
  const resultsPerMessage = 100;
  
  String getPostUrl(String project) {
    return 'https://pubsub.googleapis.com/v1/projects/$project'
        '/topics/results:publish';
  }
  
  main(List<String> args) async {
    final parser = new ArgParser();
  