def METHOD_NAME(self):
    def _clean_total_row(val, col):
        if isinstance(val, numbers.Number):
            return val
        elif col.calculate_total:
            return 0
        return ''
    qc = self.query_context()
    session_helper = connection_manager.get_session_helper(self.engine_id, readonly=True)
    with session_helper.session_context() as session:
        totals = qc.totals(
            session.connection(),
            self.total_column_ids,
            self.filter_values
        )
    total_row = [
        _clean_total_row(totals.get(column_id), col)
        for column_id, col in self.final_column_ids.items()
    ]
    if total_row and total_row[0] == '':
        total_row[0] = gettext('Total')
    return total_row