public function col_classname($row) : string {
        $output = '';
        if (class_exists($row->classname)) {
            $task = new $row->classname;
            if ($task instanceof \core\task\scheduled_task) {
                $output = $task->get_name();
            }
        }

        $output .= \html_writer::tag('div', "\\{$row->classname}", [
                'class' => 'task-class',
            ]);
        return $output;
    }