/// <summary>
/// Request access token for an app key, client secret and authorization code
/// </summary>
/// <param name="httpContext">current application context</param>
/// <param name="code">authorization code</param>
/// <returns>access token</returns>
public static string GetAccessTokenByCode(HttpContext httpContext, string code)
{
var webForm = new AuthenticationWebPage(httpContext, null);
return webForm.GetAccessTokenByCode(code);
}
