public static function audience_options($any = false) {
        $options = array();
        if ($any) {
            $options['all'] = get_string('any');
        }
        $options[self::HUB_AUDIENCE_EDUCATORS] = get_string('audienceeducators', 'hub');
        $options[self::HUB_AUDIENCE_STUDENTS] = get_string('audiencestudents', 'hub');
        $options[self::HUB_AUDIENCE_ADMINS] = get_string('audienceadmins', 'hub');
        return $options;
    }