code: func (h *HTTPBin) Gzip(w http.ResponseWriter, r *http.Request) {
  	resp := &gzipResponse{
  		Headers: getRequestHeaders(r),
  		Origin:  getOrigin(r),
  		Gzipped: true,
  	}
  	body, _ := json.Marshal(resp)
  
  	buf := &bytes.Buffer{}
  	gzw := gzip.NewWriter(buf)
  	gzw.Write(body)
  	gzw.Close()
  
  	gzBody := buf.Bytes()
  
  	w.Header().Set("Content-Encoding", "gzip")
  	writeJSON(w, gzBody, http.StatusOK)
  }
docs: // Gzip returns a gzipped response