code: func (api *API) ZoneAccessRule(zoneID string, accessRuleID string) (*AccessRuleResponse, error) {
  	return api.retrieveAccessRule("/zones/"+zoneID, accessRuleID)
  }
docs: // ZoneAccessRule returns the details of a zone's access rule.
  //
  // API reference: https://api.cloudflare.com/#firewall-access-rule-for-a-zone-list-access-rules