WP_Classic_To_Block_Menu_Converter::convert( WP_Term $menu ): string|WP_Error

27	public static function convert( $menu ) {28 29		if ( ! is_nav_menu( $menu ) ) {30			return new WP_Error(31				'invalid_menu',32				__( 'The menu provided is not a valid menu.' )33			);34		}35 36		$menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );37 38		if ( empty( $menu_items ) ) {39			return '';40		}41 42		// Set up the $menu_item variables.43		// Adds the class property classes for the current context, if applicable.44		_wp_menu_item_classes_by_context( $menu_items );45 46		$menu_items_by_parent_id = static::group_by_parent_id( $menu_items );47 48		$first_menu_item = isset( $menu_items_by_parent_id[0] )49			? $menu_items_by_parent_id[0]50			: array();51 52		$inner_blocks = static::to_blocks(53			$first_menu_item,54			$menu_items_by_parent_id55		);56 57		return serialize_blocks( $inner_blocks );58	}