protected function get_post($postid) {
        if (empty($this->postsdata[$postid])) {
            $this->postsdata[$postid] = forum_get_post_full($postid);
            if (!$this->postsdata[$postid]) {
                throw new \dml_missing_record_exception('forum_posts');
            }
        }
        return $this->postsdata[$postid];
    }