code: def _is_duplicate_record(self, rtype, name, content):
          
          records = self._list_records(rtype, name, content)
          is_duplicate = len(records) >= 1
          if is_duplicate:
              LOGGER.info('Duplicate record %s %s %s, NOOP', rtype, name, content)
          return is_duplicate
docs: Check if DNS entry already exists.