public function refresh_search()
    {
        if (!empty($this->search_string)) {
            $this->search(
                is_object($this->search_set) ? $this->search_set->get_parameters('MAILBOX') : '',
                $this->search_string,
                $this->search_charset,
                $this->search_sort_field
            );
        }

        return $this->get_search_set();
    }