code: public TldExtensionType<TagType<T>> getOrCreateTagExtension()
     {
        List<Node> nodeList = childNode.get("tag-extension");
        if (nodeList != null &&  nodeList.size() > 0)
        {
           return new TldExtensionTypeImpl<TagType<T>>(this, "tag-extension", childNode, nodeList.get(0));
        }
        return createTagExtension();
     }
docs: If not already created, a new <code>tag-extension</code> element will be created and returned.
  Otherwise, the first existing <code>tag-extension</code> element will be returned.
  @return the instance defined for the element <code>tag-extension</code>