code: func newIPTRuleTemplate(action iptAction, tmpl string) *iptRuleTemplate {
  	t, err := template.New("").Parse(tmpl)
  	if err != nil {
  		panic(fmt.Sprintf("Failed to parse iptables template: %q: %v", tmpl, err))
  	}
  	return &iptRuleTemplate{action, t}
  }
docs: // newIPTRuleTemplate creates a new iptRuleTemplate.