using (HttpClientHandler handler = new HttpClientHandler())
            {
                handler.Proxy = new WebProxy(proxy.IP);
                handler.UseProxy = true;
                using (HttpClient client = new HttpClient())
                {
                    client.Timeout = TimeSpan.FromMilliseconds(Timeout);
                    Stopwatch sw = new Stopwatch();
                    sw.Start();
                    string responseString = client.GetStringAsync(ProxyJudgeUri).Result;
                    sw.Stop();
                    proxy.Timeout = sw.ElapsedMilliseconds;