public bool IsActiveUrl(string url) { if (url == null) { throw new ArgumentNullException(nameof(url)); } var cacheKey = $"url_status{url}"; if (!_statusCache.Exists(cacheKey)) { _statusCache.SetValue(cacheKey, _webRequestHelper.IsActiveUrl(url)); } return(_statusCache.GetValue(cacheKey).ToString() == true.ToString()); }