code: def fetchone(self):
          
          self._assert_valid_result_set()
          result = self.result_set.fetch_row()
          if len(result) == 0:
              return None
          else:
              return result
docs: Returns a single row of a result set. Requires an active result set on the database
          generated with ``execute()`` or ``executemany()``.
  
          :return: Returns ``None`` when no more rows are available in the result set