We need a simple way to simulate a login in test code

I've got an email address, a password, and a doctest to finish really quickly. I hoped to find a function somewhere (or some kind of utility, or whatever's appropriate for this), where I can just go:

    login(email, password)

and a true login is simulated in my tests (i.e. fires off the correct events, raises an exception if the credentials are invalid, etc.) Instead, all I found were a dozen or more lines of somewhat hard-to-follow code in launchbag.txt that seem to roughly achieve the end results I was hoping for.

A login function like the above would Make Life Easier for people writing test code that involves logging in. Long live laziness!