There are two reasons for this:
1. I've reconsidered my original plan to store the past games in
localStorage, because that would make it difficult to display them in
historical order, and would necessitate more complex logic for
updating and removing sessions.
2. I've been unhappy with how I did the testing of the serialization and
deserialization logic. So I redid it, and now I'm satisfied with it.
I've noticed that the testing methodology for the invalid fromStruct
method tests is not fully sound. If a check is accidentally removed that
test would not detect that, as long as it is not the very last. That is
because then the next error triggers. Therefore that will need to be
revisited.