anchor.diff:      // #define EX_USAGE	64	/* command line usage error */
       exit(64);
     }
  -
  -  var logging = result['logging'];
   
     if (!FileSystemEntity.isFileSync('example/example_server.dart')) {
       throw new StateError('Server expects to be started the '
  
positive.code:     pipeline = pipeline.addMiddleware(shelf.logRequests());
    }
  
    var handler = pipeline.addHandler(
        createStaticHandler('example/files', defaultDocument: 'index.html'));
  
    io.serve(handler, 'localhost', 8080).then((server) {
      print('Serving at http://${server.address.host}:${server.port}');
    });
  }
  
  ArgParser _getParser() => new ArgParser()
    ..addFlag('logging', abbr: 'l', defaultsTo: true, negatable: true);
  
negative.code: void main(List<String> args) {
    var parser = _getParser();
  
    int port;
    bool logging;
    bool listDirectories;
  
    try {
      var result = parser.parse(args);
      port = int.parse(result['port']);
      logging = result['logging'];
      listDirectories = result['list-directories'];
    } on FormatException catch (e) {
      stderr.writeln(e.message);
      stderr.writeln(parser.usage);
  