code: func (f *zoneFilter) EndpointZoneID(endpoint *endpoint.Endpoint, zones map[int64]string) (zoneID int64, name string) {
  	var matchZoneID int64
  	var matchZoneName string
  	for zoneID, zoneName := range zones {
  		if strings.HasSuffix(endpoint.DNSName, "."+zoneName) && len(zoneName) > len(matchZoneName) {
  			matchZoneName = zoneName
  			matchZoneID = zoneID
  			name = strings.TrimSuffix(endpoint.DNSName, "."+zoneName)
  		}
  	}
  	return matchZoneID, name
  }
docs: // EndpointZoneID determines zoneID for endpoint from map[zoneID]zoneName by taking longest suffix zoneName match in endpoint DNSName
  // returns 0 if no matches are found