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

outlines,
    regions_is_180,
    numbers,
    lon_or_obj,
    lat=None,
    lon_name="lon",
    lat_name="lat",
    method=None,
    xarray=None,
    wrap_lon=None,
):
    """
    internal function to create a mask
    """

    if not _is_numeric(numbers):
        raise ValueError("'numbers' must be numeric")

    lat_orig = lat

    lon, lat = _extract_lon_lat(lon_or_obj, lat, lon_name, lat_name)

    lon = np.asarray(lon)
    lat = np.asarray(lat)

    # automatically detect whether wrapping is necessary
    if wrap_lon is None:
        grid_is_180 = _is_180(lon.min(), lon.max())

        wrap_lon = not regions_is_180 == grid_is_180

    lon_orig = lon.copy()

abbrevs = {1:'uSq1', 2:'uSq2'}
            poly = {1: Polygon(outl1), 2: Polygon(outl2)}

            r = Regions(outlines, numbers, names, abbrevs, name)

            # arguments are now optional
            r = Regions(outlines)

        """

        super(Regions, self).__init__()

        if numbers is None:
            numbers = range(len(outlines))

        if not _is_numeric(numbers):
            raise ValueError("'numbers' must be numeric")

        outlines = _maybe_to_dict(numbers, outlines)

        names = _sanitize_names_abbrevs(numbers, names, "Region")
        abbrevs = _sanitize_names_abbrevs(numbers, abbrevs, "r")

        regions = dict()

        for n in numbers:
            regions[n] = _OneRegion(n, names[n], abbrevs[n], outlines[n])

        self.regions = regions
        self.name = name
        self.source = source