Functional tests fail with acts_as_authenticated installed

Hi, all!
How can I fake authentication within a functional test?
The problem is, after I've installed acts_as_authenticated all requests in my functional test are (correctly) redirected to login screen because test "user" is not logged in.
I need to "log in" in functional test setup method, but have no ideas about that.
Help me please.

Yours sincerely,
Damian/Three-eyed Fish

Hi, did you add a valid user and it's crenditials to the relevant
model's fixture? In any case, please post your relevant test and
associated fixtures file and we can better assist you.

-Conrad

Thank you.
Got it.
login_as :some_vaild_user
makes the trick.

Yours sincerely,
Damian/Three-eyed Fish