def count_parfors_variants(self, impl, arg_gen, **kwargs):
        """Run self.countParfors(impl, ...) on array types generated from
        arg_gen.
        """
        for args in arg_gen():
            with self.subTest(list(map(typeof, args))):
                argtys = tuple(map(typeof, args))
                # At least one parfors
                self.assertGreaterEqual(countParfors(impl, argtys), 1)
Run self.countParfors(impl, ...) on array types generated from
        arg_gen.
        
numba/tests/test_parfors.py