code: func IsInTLDMap(label string) bool {
  	label = strings.ToLower(label)
  	if _, ok := tldMap[label]; ok {
  		return true
  	} else {
  		return false
  	}
  }
docs: // IsInTLDMap checks that a label is present in the TLD map. It does not
  // consider the TLD's validity period and whether the TLD may have been removed,
  // only whether it was ever a TLD that was delegated.