code: func (pr httpProber) Probe(url *url.URL, headers http.Header, timeout time.Duration) (probe.Result, string, error) {
  	client := &http.Client{
  		Timeout:       timeout,
  		Transport:     pr.transport,
  		CheckRedirect: redirectChecker(pr.followNonLocalRedirects),
  	}
  	return DoHTTPProbe(url, headers, client)
  }
docs: // Probe returns a ProbeRunner capable of running an HTTP check.