412         with self.subTest(anext="pure-Python"):
414         with self.subTest(anext="builtin"):
415             self._check_async_iterator_anext(ait_class, anext)
417     def _check_async_iterator_anext(self, ait_class, anext):  argument
421             results.append(await anext(g))
422             results.append(await anext(g))
423             results.append(await anext(g, 'buckle my shoe'))
432             self.assertEqual(await anext(g1), 1)
433             self.assertEqual(await anext(g1), 2)
435                 await anext(g1)
437                 await anext(g1)
440             self.assertEqual(await anext(g2, "default"), 1)
441             self.assertEqual(await anext(g2, "default"), 2)
442             self.assertEqual(await anext(g2, "default"), "default")
443             self.assertEqual(await anext(g2, "default"), "default")
452             obj = anext(p, "completed")
461             obj = anext(p, "completed")
529                     results.append(await anext(ait))
546             await anext()
548             await anext(gen(), 1, 3)
550             await anext(1, gen())
552             await anext(aiterator=gen())
573             awaitable = anext(MyAsyncIter(), "default")
576             awaitable = anext(MyAsyncIter())
584         awaitable = anext(aiter_class(), "default")
587         awaitable = anext(aiter_class())
621             awaitable = anext(WithRaisingAwaitableAnext())
624             awaitable = anext(WithRaisingAwaitableAnext(), "default")
647         def test1(anext):  argument
649             with contextlib.closing(anext(agen, "default").__await__()) as g:
660         def test2(anext):  argument
662             with contextlib.closing(anext(agen, "default").__await__()) as g:
668         def test3(anext):  argument
670             with contextlib.closing(anext(agen, "default").__await__()) as g:
676         def test4(anext):  argument
691             with contextlib.closing(anext(agen, "default").__await__()) as g:
697         def test5(anext):  argument
711             with contextlib.closing(anext(agen, "default").__await__()) as g:
716         def test6(anext):  argument
727             with contextlib.closing(anext(agen, "default").__await__()) as g:
735                 test(anext)