private function handle_missing_applied_filters($filtersapplied, $filteroptions) {
        global $DB;

        foreach ($filtersapplied as $filter) {
            if (!array_key_exists($filter, $filteroptions)) {
                $filtervalue = explode(':', $filter);
                if (count($filtervalue) !== 2) {
                    continue;
                }
                $key = $filtervalue[0];
                $value = $filtervalue[1];

                switch($key) {
                    case USER_FILTER_LAST_ACCESS:
                        $now = usergetmidnight(time());
                        $criteria = get_string('usersnoaccesssince');
                        // Days.
                        for ($i = 1; $i < 7; $i++) {
                            $timestamp = strtotime('-' . $i . ' days', $now);
                            if ($timestamp < $value) {
                                break;
                            }
                            $val = get_string('numdays', 'moodle', $i);
                            $filteroptions += $this->format_filter_option(USER_FILTER_LAST_ACCESS, $criteria, $timestamp, $val);
                        }
                        // Weeks.
                        for ($i = 1; $i < 10; $i++) {
                            $timestamp = strtotime('-'.$i.' weeks', $now);
                            if ($timestamp < $value) {
                                break;
                            }
                            $val = get_string('numweeks', 'moodle', $i);
                            $filteroptions += $this->format_filter_option(USER_FILTER_LAST_ACCESS, $criteria, $timestamp, $val);
                        }
                        // Months.
                        for ($i = 2; $i < 12; $i++) {
                            $timestamp = strtotime('-'.$i.' months', $now);
                            if ($timestamp < $value) {
                                break;
                            }
                            $val = get_string('nummonths', 'moodle', $i);
                            $filteroptions += $this->format_filter_option(USER_FILTER_LAST_ACCESS, $criteria, $timestamp, $val);
                        }
                        // Try a year.
                        $timestamp = strtotime('-1 year', $now);
                        if ($timestamp >= $value) {
                            $val = get_string('numyear', 'moodle', 1);
                            $filteroptions += $this->format_filter_option(USER_FILTER_LAST_ACCESS, $criteria, $timestamp, $val);
                        }
                        break;
                    case USER_FILTER_ROLE:
                        $criteria = get_string('role');
                        if ($role = $DB->get_record('role', array('id' => $value))) {
                            $role = role_get_name($role);
                            $filteroptions += $this->format_filter_option(USER_FILTER_ROLE, $criteria, $value, $role);
                        }
                        break;
                }
            }
        }
        return $filteroptions;
    }