def save_four_ds9(rectwv_coeff, debugplot=0):
    """Save the 4 possible ds9 region files.

    Parameters
    ----------
    rectwv_coeff : RectWaveCoeff instance
        Rectification and wavelength calibration coefficients for the
        particular CSU configuration.
    debugplot : int
            Debugging level for messages and plots. For details see
            'numina.array.display.pause_debugplot.py'.

    """

    for limits, rectified, suffix in zip(
        ['frontiers', 'frontiers', 'boundaries', 'boundaries'],
        [False, True, False, True],
        ['rawimage', 'rectified', 'rawimage', 'rectified']
    ):
        output = rectwv_coeff_to_ds9(rectwv_coeff=rectwv_coeff,
                                     limits=limits,
                                     rectified=rectified)
        filename = 'ds9_' + limits + '_' + suffix + '.reg'
        if abs(debugplot) >= 10:
            print('>>> Saving: ', filename)
        save_ds9(output, filename)
Save the 4 possible ds9 region files.

    Parameters
    ----------
    rectwv_coeff : RectWaveCoeff instance
        Rectification and wavelength calibration coefficients for the
        particular CSU configuration.
    debugplot : int
            Debugging level for messages and plots. For details see
            'numina.array.display.pause_debugplot.py'.