code: def get_asn_dns(self):
          
  
          try:
  
              log.debug('ASN query for {0}'.format(self.dns_zone))
              data = self.dns_resolver.query(self.dns_zone, 'TXT')
              return list(data)
  
          except (dns.resolver.NXDOMAIN, dns.resolver.NoNameservers,
                  dns.resolver.NoAnswer, dns.exception.Timeout) as e:
  
              raise ASNLookupError(
                  'ASN lookup failed (DNS {0}) for {1}.'.format(
                      e.__class__.__name__, self.address_str)
              )
  
          except:  # pragma: no cover
  
              raise ASNLookupError(
                  'ASN lookup failed for {0}.'.format(self.address_str)
              )
docs: The function for retrieving ASN information for an IP address from
          Cymru via port 53 (DNS).
  
          Returns:
              list: The raw ASN data.
  
          Raises:
              ASNLookupError: The ASN lookup failed.