def METHOD_NAME(self, split):
    with tempfile.TemporaryDirectory() as root_dir:
        language_pair = ("de", "en")
        valid_set = "tst2013"
        test_set = "tst2014"
        _ = _get_mock_dataset(
            os.path.join(root_dir, "datasets"), split, language_pair[0], language_pair[1], valid_set, test_set
        )
        dataset1 = IWSLT2016(
            root=root_dir,
            split=split,
            language_pair=language_pair,
            valid_set=valid_set,
            test_set=test_set,
        )
        (dataset2,) = IWSLT2016(
            root=root_dir,
            split=(split,),
            language_pair=language_pair,
            valid_set=valid_set,
            test_set=test_set,
        )
        for d1, d2 in zip_equal(dataset1, dataset2):
            self.assertEqual(d1, d2)