sub vcl_recv {
if (req.restarts == 0) {
                if (req.http.x-forwarded-for != "") {
                        set req.http.x-forwarded-for = "preset-test-" + client.ip;
                        set req.http.x-forwarded-for = req.http.x-forwarded-for + ", " + client.ip;
                } else {
                        set req.http.x-forwarded-for = client.ip;
                }
        }
}