redirect_guess_404_permalink example

if ( $post_id ) {
                $redirect_url = get_permalink( $post_id );
                $redirect_obj = get_post( $post_id );

                $redirect['path']  = rtrim( $redirect['path'], (int) get_query_var( 'page' ) . '/' );
                $redirect['query'] = remove_query_arg( 'page', $redirect['query'] );
            }
        }

        if ( ! $redirect_url ) {
            $redirect_url = redirect_guess_404_permalink();

            if ( $redirect_url ) {
                $redirect['query'] = _remove_qs_args_if_not_in_url(
                    $redirect['query'],
                    array( 'page', 'feed', 'p', 'page_id', 'attachment_id', 'pagename', 'name', 'post_type' ),
                    $redirect_url
                );
            }
        }
    } elseif ( is_object( $wp_rewrite ) && $wp_rewrite->using_permalinks() ) {