def METHOD_NAME(self, actual_subvol, expected_path, expected_subvol) -> None:
    self.assertEqual(expected_path, actual_subvol.subvolume_path())
    self.assertEqual(expected_subvol, actual_subvol)
    # Automatically tests "normal case" serialization & deserialization
    fake_file = io.StringIO()
    actual_subvol.to_json_file(fake_file)
    fake_file.seek(0)
    self.assertEqual(
        actual_subvol,
        subvolume_on_disk.SubvolumeOnDisk.from_json_file(
            fake_file, actual_subvol.subvolumes_base_dir
        ),
    )