code: func (n NetworkNumber) ToIP() net.IP {
  	ip := make(net.IP, len(n)*BytePerUint32)
  	for i := 0; i < len(n); i++ {
  		idx := i * net.IPv4len
  		binary.BigEndian.PutUint32(ip[idx:idx+net.IPv4len], n[i])
  	}
  	if len(ip) == net.IPv4len {
  		ip = net.IPv4(ip[0], ip[1], ip[2], ip[3])
  	}
  	return ip
  }
docs: // ToIP returns equivalent net.IP.