Automattic\VIP\Performance\Last_Post_Modified::handle_post_transition PHP Method

    public static function handle_post_transition($new_status, $old_status, $post)
    {
        if (!in_array('publish', array($old_status, $new_status))) {
            return;
        }
        $public_post_types = get_post_types(array('public' => true));
        if (!in_array($post->post_type, $public_post_types)) {
            return;
        }
        if (self::is_locked($post->post_type)) {
            return;
        }
        self::set_lock($post->post_type);
        do_action('wpcom_vip_bump_lastpostmodified', $post);
    }