protected function prepare_form_values(WP_Form_Component $component)
 {
     if ($component instanceof WP_Form_Aggregate) {
         foreach ($component->get_children() as $child) {
             $this->prepare_form_values($child);
         }
     } elseif ($component instanceof WP_Form_Element) {
         $value = $this->get_value($component->get_name());
         $component->set_value($value);
     }
 }