_wp_reset_invalid_menu_item_parent example

 else {
                            $parent_db_id = 0;
                        }

                        $parent_object = wp_setup_nav_menu_item( get_post( $parent_db_id ) );

                        if ( ! is_wp_error( $parent_object ) ) {
                            $parent_data                        = (array) $parent_object;
                            $menu_item_data['menu_item_parent'] = $parent_data['menu_item_parent'];

                            // Reset invalid `menu_item_parent`.                             $menu_item_data = _wp_reset_invalid_menu_item_parent( $menu_item_data );

                            update_post_meta( $menu_item_data['ID'], '_menu_item_menu_item_parent', (int) $menu_item_data['menu_item_parent'] );
                        }

                        // Make menu item a child of its next sibling.                     } else {
                        $next_item_data['menu_order'] = $next_item_data['menu_order'] - 1;
                        $menu_item_data['menu_order'] = $menu_item_data['menu_order'] + 1;

                        $menu_item_data['menu_item_parent'] = $next_item_data['ID'];