I assume that you downloaded a snapshot from the Brownies download page, e.g. brownies-collections-20120925.jar.
In the offical release (currently 0.9.3) the classes SetList, MapList, and KeyList are not included, because they are not yet stable.
The snapshot release however should include all classes, but presumably something with the build went wrong.
I will try to create a new snapshot this week.
Regards,
Thomas