at_theme-1.4.1/at_core/templates/form/checkboxes.html.twig

{#
/**
 * @file
 * Theme override for a 'checkboxes' #type form element.
 *
 * Available variables
 * - attributes: A list of HTML attributes for the wrapper element.
 * - children: The rendered checkboxes.
 *
 * @see template_preprocess_checkboxes()
 */
 @todo: remove this file once https://www.drupal.org/node/1819284 is resolved.
 This is identical to core/modules/system/templates/container.html.twig
#}
<div{{ attributes.addClass('form-checkboxes') }}>{{ children }}</div>