anchor.diff:    });
   
     group('HTTP errors', () {
  -    var server;
  -    var url;
  +    HttpServer server;
  +    Uri url;
       setUp(() async {
         server = await shelf_io.serve(webSocketHandler((_) {
           fail('should not create a WebSocket');
         }), 'localhost', 0);
  -      url = 'http://localhost:${server.port}/';
  +      url = Uri.http('localhost:${server.port}', '');
       });
   
       tearDown(() => server.close());
  
positive.code:   });
  
    group('with a set of allowed origins', () {
      var server;
      var url;
      setUp(() async {
        server = await shelf_io.serve(
            webSocketHandler((webSocket) {
  
negative.code:           }, allowedOrigins: ['pub.dartlang.org', 'GoOgLe.CoM']),
            'localhost',
            0);
        url = Uri.http('localhost:${server.port}', '');
      });
  
      tearDown(() => server.close());
  