code: def _dns_lookup(name, rdtype, nameservers=None):
          
          rrset = dns.rrset.from_text(name, 0, 1, rdtype)
          try:
              resolver = dns.resolver.Resolver()
              resolver.lifetime = 1
              if nameservers:
                  resolver.nameservers = nameservers
              rrset = resolver.query(name, rdtype)
              for rdata in rrset:
                  LOGGER.debug('DNS Lookup => %s %s %s %s',
                               rrset.name.to_text(), dns.rdataclass.to_text(rrset.rdclass),
                               dns.rdatatype.to_text(rrset.rdtype), rdata.to_text())
          except dns.exception.DNSException as error:
              LOGGER.debug('DNS Lookup => %s', error)
          return rrset
docs: Looks on specified or default system domain nameservers to resolve record type
          & name and returns record set. The record set is empty if no propagated
          record found.