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 describe(self) -> None:
        """Logs a profile report after the conclusion of run."""
        # there are pickling issues with open file handles in Python 3.6
        # so to avoid them, we open and close the files within this function
        # by calling `_prepare_streams` and `teardown`
        self._prepare_streams()
        summary = self.summary()
        if summary:
            self._write_stream(summary)
        if self._output_file is not None:
            self._output_file.flush()
        self.teardown(stage=self._stage)