I considered to use `Y.Array.unique()` but it requires a compare function for non strings/numbers-only arrays that I wasn't sure about. My main concern was the risk of returning false positive to the test as I can't guarantee that a user-defined function actually works as intended.

Because YUI separated `Y.Array.dedupe()` and `Y.Array.unique()` I thought it would also make sense to keep them separated in the Test module.