We generally try to prefix the declarations in tests by something unique because (at least once upon a time, though I'm not certain it's still true) they could all get parsed at once, so having a `concat()` declared in some other file in the same directory would result in a (confusing) compile error.

Also there's a standard copyright header we try to remember to add to all new `.ceylon` and `.java` files which this file lacks. (I admit I'm probably most guilty of forgetting this).