code: def fetchone(self):
          
          if self._state == self._STATE_NONE:
              raise Exception("No query yet")
          if not self._data:
              return None
          else:
              self._rownumber += 1
              return self._data.pop(0)
docs: Fetch the next row of a query result set, returning a single sequence, or ``None`` when
          no more data is available.