code: func encodeCompactIPPortInfo(ip net.IP, port int) (info string, err error) {
  	if port > 65535 || port < 0 {
  		err = errors.New(
  			"port should be no greater than 65535 and no less than 0")
  		return
  	}
  
  	p := int2bytes(uint64(port))
  	if len(p) < 2 {
  		p = append(p, p[0])
  		p[0] = 0
  	}
  
  	info = string(append(ip, p...))
  	return
  }
docs: // encodeCompactIPPortInfo encodes an ip and a port number to
  // compactIP-address/port info.