Final state of underlying sequence in islice

[Ian]

On Nov 5, 2:51 pm, Raymond Hettinger <pyt... at rcn.com> wrote:
> You may have missed my point.  I wrote the tools, the docs, and the
> tests.
> If you interpret a "promise" in text, I can assure you it was not
> intended.  The behavior *is* undefined because I never defined it.
> I'm happy to clarify the docs to make that explicit.

Does the existence of a test case imply a guarantee?

        # Test number of items consumed     SF #1171417
        it = iter(range(10))
        self.assertEqual(list(islice(it, 3)), range(3))
        self.assertEqual(list(it), range(3, 10))