Unused. Parameter needed for compatibility with DataFrame.
        kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
            Choice of sorting algorithm. See :func:`numpy.sort` for more
            information. 'mergesort' and 'stable' are the only stable algorithms.
        order : None
            Has no effect but is accepted for compatibility with numpy.

        Returns
        -------
        Series[np.intp]
            Positions of values within the sort order with -1 indicating
            nan values.

        See Also
        --------
        numpy.ndarray.argsort : Returns the indices that would sort this array.

        Examples
        --------
        >>> s = pd.Series([3, 2, 1])
        >>> s.argsort()
        0    2
        1    1
        2    0
        dtype: int64
        rA