//
// @see \Drupal\Core\Render\Element\Checkboxes::valueCallback()
// @see https://www.w3.org/TR/html401/interact/forms.html#checkbox
//
// @see \Drupal\Core\Render\Element\Checkboxes::valueCallback()
// @see https://www.w3.org/TR/html401/interact/forms.html#checkbox