Html::checkboxList Anyway to get Vertical List?

Title kind of says it all but what argument would I pass in to get the list to show vertically instead of horizontally?

Right now I’m doing something like this:


foreach($documents as $d){

	$items[$d['id']] = $d['name'];


echo '<div class="row">';	

	echo '<div class="col-xs-10">';

		echo Html::checkboxList('doc_',['separator' => '<p>'],$items);

	echo '</div>';

echo '</div>';

And its show displaying in a horizontal line.

echo Html::checkboxList('doc_', null, $items, ['separator' => '<br>']);

So simple! Thanks!