Hmm, I don't understand why we use fallbackScope here. If we don't have a MethodInvocation, we don't care about this being repeatable (nor would we, as far as I can tell, actually have any way to repeat it), so we can just return actually random values, right?

Is this just for tests? If we need tests to behave in a different way (do we?), we should probably provide a more test-specific hook.