def METHOD_NAME(self, coord, coord_sys):
    """
    Parse single astropy.coordinates instance, list of astropy.coordinate
    instances, or 2xN list of coordinate values.
    Parameters
    ----------
    coord : list-like
    coord_sys : string
    Returns
    -------
    lon : list
        Longitude coordinate values
    lat : list
        Latitude coordinate values
    """
    if not isinstance(coord, list):
        # single astropy coordinate
        try:
            ra, dec = commons.coord_to_radec(coord)
            lon = [ra]
            lat = [dec]
            return lon, lat
        except ValueError:
            raise CoordParseError()
    elif isinstance(coord, list):
        shape = np.shape(coord)
        # list of astropy coordinates
        if len(shape) == 1:
            try:
                radec = [commons.coord_to_radec(co) for co in coord]
                lon, lat = list(zip(*radec))
                return lon, lat
            except ValueError:
                raise CoordParseError()
        # list-like of values
        elif (len(shape) == 2) & (shape[0] == 2):
            warnings.warn('Non-Astropy coordinates may not be supported '
                          'in a future version.', AstropyDeprecationWarning)
            return coord
        else:
            raise CoordParseError()
    else:
        raise CoordParseError()