After upgrading a treeview to prometheus, I am having trouble getting some client side code to work. In particular, when I do a node.get_checked(), the browser gives a javascript error: Object doesn't support this property or method. When I do a node.get_nodes(), I get a valid object back, so I know the object node is not null and some of the javascript is being loaded, but perhaps not all of it? I cannot figure out why I cannot get the get_checked() method to work.