anchor.diff:        .first;
     print('New version: $newVersion');
   
  -  final bool deleteOld = args.contains('--delete-old');
     for (String service in services) {
       print('\nDeploying $service...\n');
  -    await new _ServiceDeployer(service, newVersion, deleteOld).deploy();
  +    await new _ServiceDeployer(service, newVersion, deleteOld, migrateTraffic)
  +        .deploy();
     }
   
     httpClient.close(force: true);
  
positive.code: import 'dart:io';
  
  HttpClient httpClient = new HttpClient();
  
  Future main(List<String> args) async {
    List<String> services;
  
negative.code: 
    Future _gcloudDeploy() async {
      final String yamlFile = service == 'default' ? 'app.yaml' : '$service.yaml';
      await _runGCloudApp(
          ['deploy', yamlFile, '--no-promote', '-v', newVersion, '-q'],
          'Couldn\'t deploy $service.');
    }
  
    String get baseUrl {
  