WPCOM_VIP_Cache_Manager::queue_old_permalink_purge PHP Method

    public function queue_old_permalink_purge($post_ID, $post_after, $post_before)
    {
        if (get_permalink($post_before) !== get_permalink($post_after) && 'publish' === $post_before->post_status) {
            $this->queue_purge_url(get_permalink($post_before));
        }
    }