def METHOD_NAME(ph_nacl: Phonopy):
    """Test to reproduce proper band structure of primitive cell.
    Results are written to "bin-unfolding-test.dat".
    This data can be plotted by
    % plot_band.py bin-unfolding-test.dat
    Increase nd to get better plot.
    The test is done with nd=10.
    """
    # ph = _get_phonon(ph_nacl)
    ph = ph_nacl
    nd = 10
    qpoints = (
        np.array(
            [
                [
                    x,
                ]
                * 3
                for x in range(nd)
            ]
        )
        / float(nd)
        - 0.5
    )
    unfolding_supercell_matrix = [[-2, 2, 2], [2, -2, 2], [2, 2, -2]]
    mapping = np.arange(len(ph.supercell), dtype=int)
    unfolding = Unfolding(
        ph, unfolding_supercell_matrix, ph.supercell.scaled_positions, mapping, qpoints
    )
    unfolding.run()
    weights = _get_weights(unfolding, qpoints)
    # _write_weights(weights, "unfolding.dat")
    # filename_out = os.path.join(data_dir, "bin-unfolding-test.dat")
    _compare(weights, os.path.join(data_dir, "bin-unfolding.dat"), filename_out=None)