// the policy lookup would ambiguous.
	if r.TLS == nil {
		writeSTSErrorResponse(ctx, w, ErrSTSInsecureConnection, errors.New("No TLS connection attempt"))
		return
	}

	// A client may send a certificate chain such that we end up
	// with multiple peer certificates. However, we can only accept
	// a single client certificate. Otherwise, the certificate to
	// policy mapping would be ambiguous.

		// fmt.Printf("Upcoming: %s %s\n", req.Method, req.URL.String())
		// for i, c := range via {
		// 	fmt.Printf("Sofar %d: %s %s\n", i, c.Method, c.URL.String())
		// }
		// Save the last request in a redirect chain.
		lastReq = req
		// We do not follow redirect back to client application.
		if req.URL.Path == "/oauth_callback" {
			return http.ErrUseLastResponse
		}
		return nil
	}