code: func canonicalizeDomainNames(domains []string) []string {
  	var cDomains []string
  	for _, d := range domains {
  		if !strings.HasSuffix(d, ".") {
  			d += "."
  			cDomains = append(cDomains, strings.ToLower(d))
  		}
  	}
  	return cDomains
  }
docs: // converts domain names to FQDN