def set_session_settings(torrent_client, params):
    """
    Set speed limits

    params - session settings key=value pairs.
    More info can be found in
    <a href="http://www.rasterbar.com/products/libtorrent/manual.html#session-customization">libtorrent API docs</a>.
    :return: 'OK'
    """
    torrent_client.set_session_settings(**params)
    return 'OK'