public async Task <AccountSession> AuthenticateTokenAsync(string authCode)
{
HttpWebRequest webReq = HttpWebRequest.CreateHttp(Microsoft.OneDrive.Sdk.Authentication.OAuthConstants.MicrosoftAccountTokenServiceUrl);
webReq.Method = "POST";
webReq.ContentType = "application/x-www-form-urlencoded";
using (StreamWriter sw = new StreamWriter(await webReq.GetRequestStreamAsync()))
await sw.WriteAsync(oh.GetAuthorizationCodeRedemptionRequestBody(authCode, ClientId, null, null, ClientSecret));
using (HttpWebResponse webRes = (HttpWebResponse)webReq.GetResponse())
using (StreamReader sr = new StreamReader(webRes.GetResponseStream()))
return(accountSession = new AccountSession(JsonConvert.DeserializeObject <IDictionary <string, string> >(await sr.ReadToEndAsync())));
}