请问评论邮件回复里面的推荐阅读是如何调用的，谢谢！

/* 简单相关文章(用于邮件)
/* ------------------------------ */
function dr_mail_related_post($postid){
    $tags = wp_get_post_tags($postid);
    $tagIDs = array();
    $related = '';

    if ($tags) {
        $tagcount = count($tags);
        for ($i = 0;$i <$tagcount;$i++) {
            $tagIDs[$i] = $tags[$i]->term_id;
        }

        $args=array(
            'tag__in'=>$tagIDs,
            'post__not_in'=>array($postid),
            'showposts'=>5,
            'orderby'=>'rand',
            'caller_get_posts'=>1
        );

        $my_query = new WP_Query($args);
        if( $my_query->have_posts() ) {
            $related = '<h3 style="padding-left:10px;margin:10px 0 5px;font-size:16px;font-weight:bold;border-left:3px solid #1cbdc5;line-height:25px;height:25px;">'.__('相关文章','tinection').'</h3><ul>';

            while ($my_query->have_posts()) : $my_query->the_post();
                $related .= '<li style="list-style:circle;font-size:13px;"><a style="color:#1cbdc5;font-size:13px;font-family:微软雅黑,Microsoft Yahei;" href="'; $related .= get_permalink();
                $related .= '" rel="bookmark" title="';
                $related .= get_the_title($post->ID);
                $related .= '">';
                $related .= get_the_title($post->ID);
                $related .= ' ( ';
                $related .= get_comments_number($post->ID); $related .= ' ) ';
                $related .= '</a></li>';
            endwhile;

            $related .= '</ul>';
        }
        wp_reset_postdata();
    }

    return $related;
}