code: func FetchURL(source string, timeout time.Duration) (io.ReadCloser, error) {
  	resp, err := httpGet(source, timeout)
  	if err != nil {
  		return nil, fmt.Errorf("http fetch %s: %v", source, err)
  	}
  	if resp.StatusCode != http.StatusOK {
  		return nil, fmt.Errorf("server response: %s", resp.Status)
  	}
  
  	return resp.Body, nil
  }
docs: // FetchURL fetches a profile from a URL using HTTP.