I can't see a way to nest using Injector. Though I could store the entire injector inst and reset it in the teardown, rather than just the CookieJar.

On another topic I'd suggest nesting config and injector per test should be part of the core SapphireTest to stop config leaks. We have to do this manually in all our tests at the moment which seems a bit redundant. We'll probably open a PR for that in the future