private DomElement addChild(final DomElement element, final Type type, final int index) {
    try {
      final DomInvocationHandler handler = DomManagerImpl.getDomInvocationHandler(element);
      assert handler != null;
      return handler.addCollectionChild(this, type, index);
    }
    catch (IncorrectOperationException e) {
      throw new RuntimeException(e);
    }
  }
private DomElement addChild(final DomElement element, final Type type, final int index)