def fetchone(self):
self._check_executed()<EOL>if self.rownumber >= len(self._rows): return None<EOL>result = self._rows[self.rownumber]<EOL>self.rownumber = self.rownumber+<NUM_LIT:1><EOL>return result<EOL>
Fetches a single row from the cursor. None indicates that
        no more rows are available.