t the row and column labels before forming the sparse matrix.
        When `row_levels` and/or `column_levels` refer to a single level,
        set to `True` for a faster execution.

    Returns
    -------
    values : numpy.ndarray
        Valid values to populate a sparse matrix, extracted from
        ss.
    i_coords : numpy.ndarray (row coordinates of the values)
    j_coords : numpy.ndarray (column coordinates of the values)
    i_labels : list (row labels)
    j_labels : list (column labels)
    )