public static IStateFormatter CreateFormatter()
{
HttpResponse response = new HttpResponse(TextWriter.Null);
HttpRequest request = new HttpRequest("__token__.aspx",
HttpContext.Current.Request.Url.ToString(), "__EVENTTARGET=true&__VIEWSTATEENCRYPTED=true");
HttpContext context = new HttpContext(request, response);
Page page = new Page();
page.EnableViewStateMac = true;
page.ViewStateEncryptionMode = ViewStateEncryptionMode.Always;
page.ProcessRequest(context);
return new TokenPersister(page).StateFormatter;
}