public function add_bundle_setting_form_validate($form, &$form_state, $bundle, $type_location)
 {
     // Ensure that revisions are enabled if panelizer revisions are.
     if ($form_state['values']['node_options']['panelizer']) {
         $form_state['values']['node_options']['revision'] = 1;
     }
     parent::add_bundle_setting_form_validate($form, $form_state, $bundle, $type_location);
 }