apply_filters( "get_{$adjacent}_post_sort", string $order_by, WP_Post $post, string $order )

1998	 * @since 4.9.0 Added the `$order` parameter.1999	 *2000	 * @param string $order_by The `ORDER BY` clause in the SQL.2001	 * @param WP_Post $post    WP_Post object.2002	 * @param string  $order   Sort order. 'DESC' for previous post, 'ASC' for next.2003	 */2004	$sort = apply_filters( "get_{$adjacent}_post_sort", "ORDER BY p.post_date $order LIMIT 1", $post, $order );2005 2006	$query        = "SELECT p.ID FROM $wpdb->posts AS p $join $where $sort";2007	$key          = md5( $query );2008	$last_changed = wp_cache_get_last_changed( 'posts' );2009	if ( $in_same_term || ! empty( $excluded_terms ) ) {2010		$last_changed .= wp_cache_get_last_changed( 'terms' );