code: func ReplaceDomainPrefix(host string, replaceBy string) (string, error) {
  	split := strings.SplitN(host, ".", 2)
  	if len(split) < 2 {
  		return host, errors.NewBadParameterError("host", host).Expected("must contain more than one domain")
  	}
  	return replaceBy + "." + split[1], nil
  }
docs: // ReplaceDomainPrefix replaces the last name in the host by a new name. Example: api.service.domain.org -> sso.service.domain.org