[dev] Help: customer <-> group relation out of CVS / how to set up or test?

I checked dev mailing list. And found some discussion about customer <-> group relationship available in CVS code. I am running kernel 1.1.3. I have checked out cvs source code, and laid it on top of kernel. But what else do I need to do in order to enable this new feature in CVS? Because after checking out CVS, I am seeing no changes at all when I log in as an agent and into admin area. Thanks for the help. Alex