protected function getThreadForGuests()
    {
        return $this->_query->joinWith([
                'forum' => function ($query) {
                    $query->andWhere([
                            Forum::tableName() . '.visible' => 1
                        ])->joinWith(['category' => function ($query) {
                            $query->andWhere([Category::tableName() . '.visible' => 1]);
                        }]);
                }
            ])->limit(1)->one();
    }