list-widget.php

<ul class="<?= implode(' ', $css_classes) ?>" aria-label="<?= htmlReady($title) ?>">
<? foreach ($elements as $index => $element): ?>
    <li id="<?= htmlReady($index) ?>"
        <?= !empty($element->active) ? 'class="active"' : '' ?>>
        <?= $element->render() ?>
    </li>
<? endforeach; ?>
</ul>