protected override WebRequest GetWebRequest(Uri uri)
        {
            var wr = base.GetWebRequest(uri);

            wr.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");

            if (authentication is SAML)
            {
                wr.Headers.Add("Cookie", string.Format("FedAuth={0}", SAML.GetToken(siteUrl)));
            }

            return(wr);
        }