@Override
  public final DomElement createPathStableCopy() {
    final DomFixedChildDescription description = getChildDescription();
    final DomElement parentCopy = getParent().createStableCopy();
    return getManager().createStableValue(
      (Factory<DomElement>)() -> parentCopy.isValid() ? description.getValues(parentCopy).get(myIndex) : null);
  }
@Override
  public final DomElement createPathStableCopy()