[Plugin: NextGEN Gallery] TAGCOULD not there

i’ve tried to do this:
http://nextgen.boelinger.com/tag-cloud/

but it doesn’t work.

then i did a folder-search for the term ‘tagcloud’ and it doesn’t exist in the ‘nextgen-gallery’ plugin folder or in the ‘shortcodes.php’ – so i guess how could it work?

any idea about how to accomplish this?
http://nextgen.boelinger.com/tag-cloud/