public override void ProcessSignInRequest(Scope scope, HttpContextBase httpContext)
{
Logger.Info(string.Format("process signin request! Identifier: {0}, ReplyUrl: {1}", MultiProtocolIssuer.Identifier, MultiProtocolIssuer.ReplyUrl));
var identityProviderUrl = string.IsNullOrEmpty(_wsfedEndpoint) ? Issuer.Url.ToString() : _wsfedEndpoint;
RequestAuthentication(httpContext, identityProviderUrl, MultiProtocolIssuer.Identifier.ToString(), MultiProtocolIssuer.ReplyUrl.ToString());
}