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 delete_lines(self, min_row, max_row):
        if min_row == -1:
            self.current_label.fuzz_values = self.current_label.fuzz_values[:-1]
        else:
            self.current_label.fuzz_values = self.current_label.fuzz_values[:min_row] + self.current_label.fuzz_values[
                                                                                        max_row + 1:]

        _ = self.current_label  # if user deleted all, this will restore a fuzz value

        self.fuzz_table_model.update()