def _difference(idxs):
    """ Returns the chained difference of the indexes given.

    Parameters
    ----------
    idxs : list
        List of pandas.Index objects.

    Returns
    -------
    idx : pandas.Index
        The result of the chained difference of the indexes
        given.
    """
    idx = idxs[0]
    for idx_part in idxs[1:]:
        idx = idx.difference(idx_part)
    return idx