Contao\Automator::purgeUndoTable PHP Method

    public function purgeUndoTable()
    {
        $objDatabase = \Database::getInstance();
        // Truncate the table
        $objDatabase->execute("TRUNCATE TABLE tl_undo");
        // Add a log entry
        $this->log('Purged the undo table', __METHOD__, TL_CRON);
    }