code: def _guess_record(self, rtype, name=None, content=None):
          
          records = self._list_records_internal(
              identifier=None, rtype=rtype, name=name, content=content)
          if len(records) == 1:
              return records[0]
          if len(records) > 1:
              raise Exception(
                  'Identifier was not provided and several existing '
                  'records match the request for {0}/{1}'.format(rtype, name))
          raise Exception(
              'Identifier was not provided and no existing records match '
              'the request for {0}/{1}'.format(rtype, name))
docs: Tries to find existing unique record by type, name and content