/**
  * @return AbstractFrameDecorator
  */
 function get_last_child()
 {
     $c = $this->_frame->get_last_child();
     if ($c && ($deco = $c->get_decorator())) {
         while ($tmp = $deco->get_decorator()) {
             $deco = $tmp;
         }
         return $deco;
     } else {
         if ($c) {
             return $c;
         }
     }
     return null;
 }