by 'first method called' and 'last method called' I assume your referring the first/last method called on the mock?

i dont think that adds a great deal of value in this scenario, unless you're able to enumerate every method call on the mock so you know categorically what the first and the last method called where.  It's also one of those checks, that by its nature, is brittle. Any refactor to ``saveChanges`` or ``storeChanges`` would alter the mock method invocation count.

Personally IMHO, I'd leave this as ``$this->once``.