The EquivalenceOracle interface does not seem to allow for guaranteed determinism

[stateMachinist]

findCounterExample expects inputs in the form of a Collection. However, this type does not guarantee an order over entries. This can be an issue when trying to implement reproducible sampling from the alphabet (e.g. as RandomWp does here; even though it samples from an ordered alphabet, the order may not be deterministic depending on the original collection type). This means that test word selection may in some cases depend on unpredictable runtime context. That may not be much of a problem in practice, but it does seem like a potential trip hazard to me. Then again, maybe I am expecting too many guardrails. What do you think?

Edit: On second thought, enforcing an ordered collection at this interface would only shift the problem. Formally, an alphabet is just a set, and any ordering over symbols requires a concretization from the abstract state machine formalism. I still think it may be a little bit cleaner when this concretization is forced to happen before learning begins (i.e. when setting up the experiment). But that's a debatable position, relating to our previous semantic discussion about the difference between algorithms and implementations.