def METHOD_NAME(region):
    """Create list of regions from compound regions.
    Parameters
    ----------
    region : `~regions.CompoundSkyRegion` or `~regions.SkyRegion`
        Compound sky region
    Returns
    -------
    regions : `~regions.Regions`
        List of regions.
    """
    regions = Regions([])
    if isinstance(region, CompoundSkyRegion):
        if region.operator is operator.or_:
            regions_1 = METHOD_NAME(region.region1)
            regions.extend(regions_1)
            regions_2 = METHOD_NAME(region.region2)
            regions.extend(regions_2)
        else:
            raise ValueError("Only union operator supported")
    else:
        return Regions([region])
    return regions