def pred_filter_external_download_links(package_name, href, title):
    """
    Predicate used to filter external download links.  Currently, the only
    config value is ``allowed_extensions``.

    :param string package_name:
        Name of the Python package to retrieve and filter the simple page for.
    :param href:
        Absolute URL pointing to a downloadable file on a third-party web site.
    :param title:
        Text component of the link from the simple page.  This can include
        suffixes such as `download_url` and `home_page`, which can be used as
        part of the filter.
    :returns:
        :const:`True` if the external download link should be included in the
        output, :const:`False` otherwise.
    """
    return 'download_url' in title
