code: func RedirectedRequest(r *http.Request, newUrl string) (ret *http.Request, err error) {
  	u, err := url.Parse(newUrl)
  	if err != nil {
  		return
  	}
  	ret = new(http.Request)
  	*ret = *r
  	ret.Header = nil
  	err = deepCopy(&ret.Header, r.Header)
  	if err != nil {
  		return
  	}
  	ret.URL = u
  	ret.RequestURI = ""
  	return
  }
docs: // Takes a request, and alters its destination fields, for proxying.