@Override
    public T retrieveDomElement() {
      final DomElement parent = myParent.retrieveDomElement();
      if (parent == null) return null;

      final List<? extends DomElement> list = myDescr.getValues(parent);
      if (myIndex < 0 || myIndex >= list.size()) return null;

      //noinspection unchecked
      return (T)list.get(myIndex);
    }
@Override
    public T retrieveDomElement()