code: func validIP(ip net.IP) bool {
  	if len(ip) == 4 {
  		return true
  	}
  
  	if len(ip) == 16 {
  		return true
  	}
  
  	return false
  }
docs: // validIP takes an IP address (which is implemented as a byte slice)
  // and ensures that it is a possible address. Right now, this means
  // just doing length checks.