wp-includes/class-wp-classic-to-block-menu-converter.php:67Returns an array of menu items grouped by the id of the parent menu item.
array private static function group_by_parent_id( $menu_items ) { $menu_items_by_parent_id = array(); foreach ( $menu_items as $menu_item ) { $menu_items_by_parent_id[ $menu_item->menu_item_parent ][] = $menu_item; } return $menu_items_by_parent_id; }Introduced in 6.3.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-classic-to-block-menu-converter.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.