code: func GetDNSRecordIdx(records []DNSRecord, record DNSRecord) (int, error) {
  	for index, element := range records {
  		if record.Destination == element.Destination && record.RecordType == element.RecordType {
  			return index, nil
  		}
  	}
  	return -1, fmt.Errorf("no DNS Record found")
  }
docs: // GetDNSRecordIdx searches a given array of DNSRecords for a given DNSRecord
  // equivalence is determined by Destination and RecortType attributes
  // returns index of given DNSRecord in given array of DNSRecords