// Generate response header "Link: <HREF>; rel=preconnect"
// HREF is provided by the request header X-Link

function handleRequest(request, response) {
  response.setHeader("Cache-Control", "no-cache", false);
  response.setHeader(
    "Link",
    "<" +
      request.queryString +
      ">; rel=preconnect" +
      ", " +
      "<" +
      request.queryString +
      ">; rel=preconnect; crossOrigin=anonymous"
  );
  response.write("check that header");
}