anchor.diff:  
     Future _deleteOldVersion() async {
       if (_oldVersion == null) return;
  -    final pr = await Process.run('gcloud',
  -        ['app', 'versions', 'delete', '--service', service, _oldVersion, '-q']);
  +    final pr = await _runGCloudApp(
  +        ['versions', 'delete', '--service', service, _oldVersion, '-q']);
       if (pr.exitCode != 0) {
         print('[ERR] Couldn\'t delete old version of $service.');
         print(pr.stderr);
         exit(1);
       }
     }
  +
  +  Future<ProcessResult> _runGCloudApp(List<String> args) => Process.run(
  +      'gcloud',
  +      [
  +        '--project',
  +        project,
  +        'app',
  +      ]..addAll(args));
   }
  
positive.code: 
    Future _migrateTraffic() async {
      final List<String> args = [
        'app',
        'services',
        'set-traffic',
        service,
  
negative.code: 
    Future _gcloudDeploy() async {
      final String yamlFile = service == 'default' ? 'app.yaml' : '$service.yaml';
      final pr = await _runGCloudApp(
        ['deploy', yamlFile, '--no-promote', '-v', newVersion, '-q'],
      );
      if (pr.exitCode != 0) {
        print('[ERR] Couldn\'t deploy $service.');
  