def test_previous_managed_ids_returns_none_for_missing_file(self):
    missing_path = os.path.join("some", "stupid", "path")
    self.assertFalse(os.path.exists(missing_path))

    archive = ManagedROMArchive(missing_path)
    self.assertIsNone(archive.previous_managed_ids(self.mock_user))