*  @param ns a list of namespaces to filter by, empty = all namespaces.
     *  @return the contributions of the user
     *  @throws IOException if a network error occurs
     *  @since 0.17
     */
    public Wiki.Revision[] contribs(String user, int... ns) throws IOException
    {
        return contribs(user, "", null, null, ns);
    }