code: func spliceIP(baseIP, partialIP string) string {
  	baseParts := strings.Split(baseIP, ".")
  	partialParts := strings.Split(partialIP, ".")
  	finalParts := append(baseParts[:(len(baseParts)-len(partialParts))], partialParts...)
  	return strings.Join(finalParts, ".")
  }
docs: // FIXME this only handles IPv4 at the moment