first two sessions

I am a little behind, had some trouble getting used to git. Here is the first two sessions. 
Unit tests should assert that the actual answer computed from a function or method match an expected value. In this case, there's no such assertion being done. It's expected that a human will visually check the results.

We would rather have the computer do mundane check tasks like that instead of relying on a human. Humans make mistakes. Humans don't scale up real well. You should rework the block of code in the test to hard code some expected values in the code and then check that the ack function produces the correct result.