def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def teardown(self, stage: Optional[str] = None) -> None:
        """
        Execute arbitrary post-profiling tear-down steps.

        Closes the currently open file and stream.
        """
        self._write_stream = None
        if self._output_file is not None:
            self._output_file.close()
            self._output_file = None  # can't pickle TextIOWrapper