Initial unit tests

Mmm. That could be.

If your plan is to expose that class to the caller. He/she will need to create an interval object in order to perform a query. More complex on one hand but more explicit on the other.

If your plan is to not expose it and use it only internally to simplify implementation. The code handling the interval is not specially big or complex but it's true that some encapsulation would be nice.

So in both cases, looks like a border case between needing a separate class and not needing it to me. I can convince myself of both :wink: