public function set_search_set($set)
    {
        $set = (array)$set;

        $this->search_string     = $set[0];
        $this->search_set        = $set[1];
        $this->search_charset    = $set[2];
        $this->search_sort_field = $set[3];
        $this->search_sorted     = $set[4];
        $this->search_threads    = is_a($this->search_set, 'rcube_result_thread');

        if (is_a($this->search_set, 'rcube_result_multifolder')) {
            $this->set_threading(false);
        }
    }