code: func (f *filter) EndpointZoneID(endpoint *endpoint.Endpoint, zones map[string]string) (zoneID string) {
  	var matchZoneID, matchZoneName string
  	for zoneID, zoneName := range zones {
  		if strings.HasSuffix(endpoint.DNSName, zoneName) && len(zoneName) > len(matchZoneName) {
  			matchZoneName = zoneName
  			matchZoneID = zoneID
  		}
  	}
  	return matchZoneID
  }
docs: // EndpointZoneID determines zoneID for endpoint from map[zoneID]zoneName by taking longest suffix zoneName match in endpoint DNSName
  // returns empty string if no match found