def test_input_transformed_list_of_lists_of_series(self):
        """
        Tests for correct transformation of multiple series when
        different param values are used for different parallel
        jobs (i.e. test that `parallel_params` argument is treated
        correctly). Also tests that transformer correctly handles
        being provided with fewer input series than fixed parameter
        value sets.
        """
        test_input_1 = constant_timeseries(value=1, length=10)
        test_input_2 = constant_timeseries(value=2, length=11)

        # Don't have different params for different jobs:
        mock = self.DataTransformerMock(scale=2, translation=10, parallel_params=False)
        (transformed_1, transformed_2) = mock.transform((test_input_1, test_input_2))
        # 2 * 1 + 10 = 12
        assert transformed_1 == constant_timeseries(value=12, length=10)
        # 2 * 2 + 10 = 14
        assert transformed_2 == constant_timeseries(value=14, length=11)

        # list of lists of series must get input back
        inv = mock.inverse_transform([[transformed_1], [transformed_2]])
        assert len(inv) == 2
        assert all(
            isinstance(series_list, list) and len(series_list) == 1
            for series_list in inv
        )
        assert all(
            isinstance(series, TimeSeries)
            for series_list in inv
            for series in series_list
        )
        assert inv[0][0] == test_input_1
        assert inv[1][0] == test_input_2

        # one list of lists of is longer than others, must get input back
        inv = mock.inverse_transform([[transformed_1, transformed_1], [transformed_2]])
        assert len(inv) == 2
        assert len(inv[0]) == 2 and len(inv[1]) == 1
        assert all(isinstance(series_list, list) for series_list in inv)
        assert all(
            isinstance(series, TimeSeries)
            for series_list in inv
            for series in series_list
        )
        assert inv[0][0] == test_input_1
        assert inv[0][1] == test_input_1
        assert inv[1][0] == test_input_2

        # different types of Sequences, must get input back
        inv = mock.inverse_transform(((transformed_1, transformed_1), (transformed_2,)))
        assert len(inv) == 2
        assert len(inv[0]) == 2 and len(inv[1]) == 1
        assert all(isinstance(series_list, list) for series_list in inv)
        assert all(
            isinstance(series, TimeSeries)
            for series_list in inv
            for series in series_list
        )
        assert inv[0][0] == test_input_1
        assert inv[0][1] == test_input_1
        assert inv[1][0] == test_input_2

        # one list of lists is empty, returns empty list as well
        inv = mock.inverse_transform([[], [transformed_2, transformed_2]])
        assert len(inv) == 2
        assert len(inv[0]) == 0 and len(inv[1]) == 2
        assert all(isinstance(series_list, list) for series_list in inv)
        assert all(isinstance(series, TimeSeries) for series in inv[1])
        assert inv[1][0] == test_input_2
        assert inv[1][1] == test_input_2

        # more list of lists than used during transform works
        inv = mock.inverse_transform([
            [transformed_1],
            [transformed_2],
            [transformed_2],
        ])
        assert len(inv) == 3
        assert all(
            isinstance(series_list, list) and len(series_list) == 1
            for series_list in inv
        )
        assert all(
            isinstance(series, TimeSeries)
            for series_list in inv
            for series in series_list
        )
        assert inv[0][0] == test_input_1
        assert inv[1][0] == test_input_2
        assert inv[2][0] == test_input_2

        Tests for correct transformation of multiple series when
        different param values are used for different parallel
        jobs (i.e. test that `parallel_params` argument is treated
        correctly). Also tests that transformer correctly handles
        being provided with fewer input series than fixed parameter
        value sets.
        
darts/tests/dataprocessing/transformers/test_invertible_data_transformer.py