def test_generate_index_with_start_length(self, config):
        """Test that generate index returns the expected length, start, and end points
        using `start`, `length`, and `freq` as input.
        """
        start, expected_end, freq, n_steps = config
        if isinstance(start, str):
            freq = pd.tseries.frequencies.to_offset(freq)
            start = pd.Timestamp(start)
            expected_end = (
                pd.Timestamp(expected_end) if expected_end is not None else None
            )
        idx = generate_index(start=start, length=n_steps, freq=freq)
        assert len(idx) == n_steps
        if n_steps == 0:
            return

        assert idx[-1] == expected_end
        assert idx[0] == expected_end - (n_steps - 1) * freq
Test that generate index returns the expected length, start, and end points
        using `start`, `length`, and `freq` as input.
        
darts/tests/utils/test_utils.py