For this code review assessment, take a look at the example classes. Each file is self contained: it might define a handful of classes relevant to 1 example, but no classes in any example file refer to any class from another example file.
You do not have to rewrite these methods/classes (though you can if you want). We just ask that you review these examples and come up with some comments you might give if this was someone else's PR you were asked to review.
We will meet with you to talk over these examples and your thoughts on them. There, you can explain what you might change or questions you might ask a developer who submitted this code, as well as explain what you think the given code actually does.