BetterHttpClient.ProxyManager.PostPage C# (CSharp) Метод

        public string PostPage(string url, NameValueCollection data, string requiredString = null, CookieContainer cookies = null, NameValueCollection customHeaders = null)
        {
            if (requiredString == null)
                requiredString = RequiredString;

            string page = null;
            int limit = 0;

            do
            {
                Proxy proxy = GetAvalibleProxy();
                
                try
                {
                    if (AnonymousProxyOnly)
                    {
                        if (AnonymousProxyOnly && !proxy.IsAnonymous(ProxyJudgeService))
                        {
                            continue;
                        }
                    }

                    var bytes = DownloadBytes(url, data, proxy, cookies, customHeaders);

                    if (bytes != null)
                    {
                        page = Encoding.GetString(bytes);
                        if (!page.Contains(requiredString))
                        {
                            proxy.IsOnline = false;
                        }
                        else
                        {
                            return page;
                        }
                    }
                }
                finally
                {
                    limit++;
                    proxy.IsBusy = false;
                }

                limit++;
            } while (limit < _numberOfAttemptsPerRequest);

            throw new AllProxiesBannedException();
        }