netaddress.go
func NewNetAddressIPPort(ip net.IP, port uint16) *NetAddress {
	na := &NetAddress{
		IP:   ip,
		Port: port,
		str: net.JoinHostPort(
			ip.String(),
			strconv.FormatUint(uint64(port), 10),
		),
	}
	return na
}
func NewNetAddressIPPort(ip net.IP, port uint16) *NetAddress {
	na := &NetAddress{
		IP:   ip,
		Port: port,
		str: net.JoinHostPort(
			ip.String(),
			strconv.FormatUint(uint64(port), 10),
		),
	}
	return na
}
// NewNetAddressIPPort returns a new NetAddress using the provided IP
// and port number.