code: public function renderTemplate(CollectionElement $collection)
      {
          if (false != ($sElementLayout = $collection->getOption('twb-layout'))) {
              $elementOrFieldset = $collection->getTemplateElement();
              $elementOrFieldset->setOption('twb-layout', $sElementLayout);
          }
  
          return parent::renderTemplate($collection);
      }
docs: Only render a template
  
  @param CollectionElement $collection
  @return string