code: func Response(req *http.Request, timeout time.Duration) (*http.Response, error) {
  	return doTryRequest(req, timeout, nil)
  }
docs: // Response is like Request, but returns the response for further
  // processing at the call site.
  // Conditions are not allowed since it would complicate signaling if the
  // response body needs to be closed or not. Callers are expected to close on
  // their own if the function returns a nil error.