anchor.diff:    var parser = new ArgParser();
     parser.addOption('port', abbr: 'p', defaultsTo: '8080');
     parser.addOption('dart-sdk');
  +  parser.addFlag('discovery');
  +  parser.addOption('server-url', defaultsTo: 'http://localhost');
   
     var result = parser.parse(args);
     var port = int.parse(result['port'], onError: (val) {
  
positive.code: library services;
  
  import 'dart:async';
  import 'dart:io';
  
  import 'package:args/args.dart';
  
negative.code:       endpointsServer.server = server;
        return endpointsServer;
      });
    }
  
    static Future<String> generateDiscovery(String sdkPath,
                                            String serverUrl) async {
      var commonServer = new CommonServer(sdkPath, new _Logger(), new _Cache());
      var apiServer = new ApiServer(prettyPrint: true)..addApi(commonServer);
      apiServer.enableDiscoveryApi(serverUrl, '/api');
      var request =
          new HttpApiRequest('GET',
                             'discovery/v1/apis/dartservices/v1/rest',
                             {}, 'application/json', new Stream.fromIterable([]));
      HttpApiResponse response = await apiServer.handleHttpRequest(request);
      return UTF8.decode(await response.body.first);
    }
  
    final int port;
  