Setting the current user id in 2.2

I'm trying to update the test-harness in 2.2, and I'm having difficulty 
"logging in" to sakai.

Here's what used to work for me:

Session session = SessionManager.getCurrentSession();
session.setUserId("admin");
session.setUserEid("admin");

But now calling UserDirectoryService.getCurrentUser().getId() returns an 
empty string.  And when I try to take actions such as adding users, 
adding sites, etc, I get a PermissionException, since user is null.

I've even tried AuthzGroupService.refreshUser("admin"), but that doesn't 
fix this either.  Does anyone have any ideas what I need to do to set 
the current userID in 2.2?

Thanks,
Josh

--
Josh Holtzman
Educational Technology Services, UC Berkeley
jholtzman@xxxxxxxxxxxx
510.643.7380

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