code: def fetchone(self):
          
          self._check_executed()
          fut = self._loop.create_future()
  
          if self._rows is None or self._rownumber >= len(self._rows):
              fut.set_result(None)
              return fut
          result = self._rows[self._rownumber]
          self._rownumber += 1
  
          fut = self._loop.create_future()
          fut.set_result(result)
          return fut
docs: Fetch the next row