public static async Task <string> HttpDownloadStringAsync(
string uri,
Configure <WebClient> clientConfigurator = null,
Action <WebHeaderCollection> headerConfigurator = null,
Action <WebRequest> requestConfigurator = null)
{
WebClient webClient = new CustomWebClient(requestConfigurator);
webClient = clientConfigurator.InvokeSafe(webClient);
headerConfigurator?.Invoke(webClient.Headers);
return(await webClient.DownloadStringTaskAsync(new Uri(uri)));
}