Как декодировать битвайз обратно?

def quadkey_to_tile(qk):
    """Get the tile corresponding to a quadkey
    Parameters
    ----------
    qk : str
        A quadkey string.
    Returns
    -------
    Tile
    """
    if len(qk) == 0:
        return Tile(0, 0, 0)
    xtile, ytile = 0, 0
    for i, digit in enumerate(reversed(qk)):
        mask = 1 << i
        if digit == "1":
            xtile = xtile | mask
        elif digit == "2":
            ytile = ytile | mask
        elif digit == "3":
            xtile = xtile | mask
            ytile = ytile | mask
        elif digit != "0":
            warnings.warn(
                "QuadKeyError will not derive from ValueError in mercantile 2.0.",
                DeprecationWarning,
            )
            raise QuadKeyError("Unexpected quadkey digit: %r", digit)
    return Tile(xtile, ytile, i + 1)