anchor.diff:        abbr: 'a', help: 'Authorization token with cloud-platform scope');
     parser.addOption('builder', abbr: 'b', help: 'The builder name');
     parser.addOption('build_number', abbr: 'n', help: 'The build number');
  +  parser.addFlag('staging',
  +      abbr: 's', help: 'use staging database', defaultsTo: false);
   
     final options = parser.parse(args);
     if (options['help']) {
       usage(parser);
     }
   
  +  useStagingDatabase = options['staging'];
     builder = options['builder'];
     buildNumber = int.parse(options['build_number']);
     builderBase = builder.replaceFirst(RegExp('-try\$'), '');
  
positive.code:           ].join(' '));
          }
        } else {
          print('No results recieved for build $buildNumber of $builder');
        }
      } else {
        print('HTTP status ${response.statusCode} received '
  
negative.code: 
  const numAttempts = 20;
  const failuresPerConfiguration = 20;
  
  bool useStagingDatabase;
  
  String get queryUrl {
    var project = useStagingDatabase ? "dart-ci-staging" : "dart-ci";
    return 'https://firestore.googleapis.com/v1/'
        'projects/$project/databases/(default)/documents:runQuery';
  }
  
  String builder;
  String builderBase;
  int buildNumber;
  