@Override
  public <T extends DomElement> T createStableCopy() {
    final DomElement parentCopy = getParent().createStableCopy();
    return getManager().createStableValue(() -> parentCopy.isValid() ? (T) getChildDescription().getValues(parentCopy).get(0) : null);
  }
@Override
  public <T extends DomElement> T createStableCopy()