/// <summary>
/// An async method to exhange authorization code for auth tokens with the auth server.
/// </summary>
public static Task <LiveLoginResult> ExchangeCodeForTokenAsync(string clientId, string clientSecret, string redirectUrl, string authorizationCode)
{
Debug.Assert(!string.IsNullOrEmpty(clientId));
Debug.Assert(!string.IsNullOrEmpty(redirectUrl));
Debug.Assert(!string.IsNullOrEmpty(authorizationCode));
string postContent = LiveAuthUtility.BuildCodeTokenExchangePostContent(clientId, clientSecret, redirectUrl, authorizationCode);
return(RequestAccessTokenAsync(postContent));
}