code: func hexCIDR(cidr string) (string, error) {
  	ip, ipnet, err := net.ParseCIDR(cidr)
  	if err != nil {
  		return "", err
  	}
  	ip = ip.Mask(ipnet.Mask)
  	hexIP := hex.EncodeToString([]byte(ip.To4()))
  	hexMask := ipnet.Mask.String()
  	return hexIP + "/" + hexMask, nil
  }
docs: // Convert a CIDR from text to a hex representation
  // Strips any masked parts of the IP, so 1.2.3.4/16 becomes hex(1.2.0.0)/ffffffff