How to use the regionmask.core.utils._find_splitpoint function in regionmask

def _mask_rasterize_split(lon, lat, polygons, numbers, fill=np.NaN, **kwargs):

    split_point = _find_splitpoint(lon)
    lon_l, lon_r = lon[:split_point], lon[split_point:]

    mask_l = _mask_rasterize(lon_l, lat, polygons, numbers=numbers)
    mask_r = _mask_rasterize(lon_r, lat, polygons, numbers=numbers)

    return np.hstack((mask_l, mask_r))

def _mask_rasterize_flip(lon, lat, polygons, numbers, fill=np.NaN, **kwargs):

    split_point = _find_splitpoint(lon)
    flipped_lon = np.hstack((lon[split_point:], lon[:split_point]))

    mask = _mask_rasterize(flipped_lon, lat, polygons, numbers=numbers)

    # revert the mask
    return np.hstack((mask[:, split_point:], mask[:, :split_point]))

def _determine_method(lon, lat):
    """ find method to be used -> prefers faster methods"""

    if equally_spaced(lon, lat):
        return "rasterize"

    if _equally_spaced_on_split_lon(lon) and equally_spaced(lat):

        split_point = _find_splitpoint(lon)
        flipped_lon = np.hstack((lon[split_point:], lon[:split_point]))

        if equally_spaced(flipped_lon):
            return "rasterize_flip"
        else:
            return "rasterize_split"

    return "shapely"