code: func validateEnsAPIs(s string) (err error) {
  	// missing contract address
  	if strings.HasPrefix(s, "@") {
  		return errors.New("missing contract address")
  	}
  	// missing url
  	if strings.HasSuffix(s, "@") {
  		return errors.New("missing url")
  	}
  	// missing tld
  	if strings.HasPrefix(s, ":") {
  		return errors.New("missing tld")
  	}
  	// missing url
  	if strings.HasSuffix(s, ":") {
  		return errors.New("missing url")
  	}
  	return nil
  }
docs: //validate EnsAPIs configuration parameter