anchor.diff:  
   void testBody(int totalConnections, bool useHeader) {
     HttpServer.bind("127.0.0.1", 0, totalConnections).then((server) {
  +    int serverCount = 0;
       server.listen(
           (HttpRequest request) {
             Expect.equals("2", request.headers.value('content-length'));
  
positive.code:         },
          onError: (e) => Expect.fail("Unexpected error $e"));
  
      int count = 0;
      HttpClient client = new HttpClient();
      for (int i = 0; i < totalConnections; i++) {
        client.get("127.0.0.1", server.port, "/")
  
negative.code:             response.listen(
                  (d) {},
                  onDone: () {
                    if (++clientCount == totalConnections) {
                      client.close();
                    }
                  });
            });
  