code: public Attributes<Entity<T>> getOrCreateAttributes()
     {
        Node node = childNode.getOrCreate("attributes");
        Attributes<Entity<T>> attributes = new AttributesImpl<Entity<T>>(this, "attributes", childNode, node);
        return attributes;
     }
docs: If not already created, a new <code>attributes</code> element with the given value will be created.
  Otherwise, the existing <code>attributes</code> element will be returned.
  @return  a new or existing instance of <code>Attributes<Entity<T>></code>