GUI Calls a Void Java Method example in tutorials seems to be broke

Just starting with niftygui and got the basics working but in the GUI Calls a Void Java Method in the wiki page when I try adding that panel to my layout.xml I get

cvc-complex-type.2.4.a: Invalid content was found starting with element 'interact'. One of
'{"":element}' is expected.

All I'm trying to do is get a onClick event from a default niftygui Button in jme3. There doesn't seem to be good examples or this or not sure where's a good place to look for simple example snippets.

Thanks in advance!

okay i think i got it now… So even if you tell nifty.fromXML what controller to use you have to also specify in the xml correct?

Yes. You could give it a whole list of controllers on fromXML. It matches them up by the types specified in the XML.