public function apply_expired_context_filters(array $expireduserids, array $unexpireduserids) : filtered_userlist {
        // The current userlist content.
        $userids = $this->get_userids();

        if (!empty($expireduserids)) {
            // Now remove any not on the list of expired users.
            $userids = array_intersect($userids, $expireduserids);
        }

        if (!empty($unexpireduserids)) {
            // Remove any on the list of unexpiredusers users.
            $userids = array_diff($userids, $unexpireduserids);
        }

        $this->set_userids($userids);

        return $this;
    }