page item in the list.
		 *
		 * @since 2.8.0
		 *
		 * @see wp_list_pages()
		 *
		 * @param string[] $css_class       An array of CSS classes to be applied to each list item.
		 * @param WP_Post  $page            Page data object.
		 * @param int      $depth           Depth of page, used for padding.
		 * @param array    $args            An array of arguments.
		 * @param int      $current_page_id ID of the current page.
		 */
		$css_classes = implode( ' ', apply_filters( 'page_css_class', $css_class, $page, $depth, $args, $current_page_id ) );
		$css_classes = $css_classes ? ' class="' . esc_attr( $css_classes ) . '"' : '';

		if ( '' === $page->post_title ) {
			/* translators: %d: ID of a post. */
			$page->post_title = sprintf( __( '#%d (no title)' ), $page->ID );
		}

		$args['link_before'] = empty( $args['link_before'] ) ? '' : $args['link_before'];
		$args['link_after']  = empty( $args['link_after'] ) ? '' : $args['link_after'];

		$atts                 = array();
		$atts['href']         = get_permalink( $page->ID );
		$atts['aria-current'] = ( $page->ID === (int) $current_page_id ) ? 'page' : '';

		/**
		 * Filters the HTML attributes applied to a page menu item's anchor element.
		 *
		 * @since 4.8.0
		 *
		 * @param array $atts {
		 *     The HTML attributes applied to the menu item's `<a>` element, empty strings are ignored.
		 *
		 *     @type string $href         The href attribute.
		 *     @type string $aria-current The aria-current attribute.
		 * }
		 * @param WP_Post $page            Page data object.
		 * @param int     $depth           Depth of page, used for padding.
		 * @param array   $args            An array of arguments.
		 * @param int     $current_page_id ID of the current page.
		 */
		$atts = apply_filters( 'page_menu_link_attributes', $atts, $page, $depth, $args, $current_page_id );

		$attributes = '';
		foreach ( $atts as $attr => $value ) {
			if ( is_scalar( $value ) && '' !== $value && false !== $value ) {
				$value       = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
				$attributes .= ' ' . $attr . '="' . $value . '"';
			}
		}

		$output .= $indent . sprintf(
			'<li%s><a%s>%s%s%s</a>',
			$css_classes,
			$attributes,
			$args['link_before'],
			/** This filter is documented in wp-includes/post-template.php */
			apply_filters( 'the_title', $page->post_title, $page->ID ),
			$args['link_after']
		);

		if ( ! empty( $args['show_date'] ) ) {
			if ( 'modified' === $args['show_date'] ) {
				$time = $page->post_modified;
			} else {
				$time = $page->post_date;
			}

			$date_format = empty( $args['date_format'] ) ? '' : $args['date_format'];
			$output     .= ' ' . mysql2date( $date_format, $time );
		}
	}

	/**
	 * Outputs the end of the current element in the tree.
	 *
	 * @since 2.1.0
	 * @since 5.9.0 Renamed `$page` to `$data_object` to match parent class for PHP 8 named parameter support.
	 *
	 * @see Walker::end_el()
	 *
	 * @param string  $output      Used to append additional content. Passed by reference.
	 * @param WP_Post $data_object Page data object. Not used.
	 * @param int     $depth       Optional. Depth of page. Default 0 (unused).
	 * @param array   $args        Optional. Array of arguments. Default empty array.
	 */
	public function end_el( &$output, $data_object, $depth = 0, $args = array() ) {
		if ( isset( $args['item_spacing'] ) && 'preserve' === $args['item_spacing'] ) {
			$t = "\t";
			$n = "\n";
		} else {
			$t = '';
			$n = '';
		}
		$output .= "</li>{$n}";
	}
}
 5.9.0
	 *
	 * @param int $menu_id The menu id to query.
	 * @return bool The value of auto_add.
	 */
	protected function get_menu_auto_add( $menu_id ) {
		$nav_menu_option = (array) get_option( 'nav_menu_options', array( 'auto_add' => array() ) );

		return in_array( $menu_id, $nav_menu_option['auto_add'], true );
	}

	/**
	 * Updates the menu's auto add from a REST request.
	 *
	 * @since 5.9.0
	 *
	 * @param int             $menu_id The menu id to update.
	 * @param WP_REST_Request $request Full details about the request.
	 * @return bool True if the auto add setting was successfully updated.
	 */
	protected function handle_auto_add( $menu_id, $request ) {
		if ( ! isset( $request['auto_add'] ) ) {
			return true;
		}

		$nav_menu_option = (array) get_option( 'nav_menu_options', array( 'auto_add' => array() ) );

		if ( ! isset( $nav_menu_option['auto_add'] ) ) {
			$nav_menu_option['auto_add'] = array();
		}

		$auto_add = $request['auto_add'];

		$i = array_search( $menu_id, $nav_menu_option['auto_add'], true );

		if ( $auto_add && false === $i ) {
			$nav_menu_option['auto_add'][] = $menu_id;
		} elseif ( ! $auto_add && false !== $i ) {
			array_splice( $nav_menu_option['auto_add'], $i, 1 );
		}

		$update = update_option( 'nav_menu_options', $nav_menu_option );

		/** This action is documented in wp-includes/nav-menu.php */
		do_action( 'wp_update_nav_menu', $menu_id );

		return $update;
	}

	/**
	 * Returns the names of the locations assigned to the menu.
	 *
	 * @since 5.9.0
	 *
	 * @param int $menu_id The menu id.
	 * @return string[] The locations assigned to the menu.
	 */
	protected function get_menu_locations( $menu_id ) {
		$locations      = get_nav_menu_locations();
		$menu_locations = array();

		foreach ( $locations as $location => $assigned_menu_id ) {
			if ( $menu_id === $assigned_menu_id ) {
				$menu_locations[] = $location;
			}
		}

		return $menu_locations;
	}

	/**
	 * Updates the menu's locations from a REST request.
	 *
	 * @since 5.9.0
	 *
	 * @param int             $menu_id The menu id to update.
	 * @param WP_REST_Request $request Full details about the request.
	 * @return true|WP_Error True on success, a WP_Error on an error updating any of the locations.
	 */
	protected function handle_locations( $menu_id, $request ) {
		if ( ! isset( $request['locations'] ) ) {
			return true;
		}

		$menu_locations = get_registered_nav_menus();
		$menu_locations = array_keys( $menu_locations );
		$new_locations  = array();
		foreach ( $request['locations'] as $location ) {
			if ( ! in_array( $location, $menu_locations, true ) ) {
				return new WP_Error(
					'rest_invalid_menu_location',
					__( 'Invalid menu location.' ),
					array(
						'status'   => 400,
						'location' => $location,
					)
				);
			}
			$new_locations[ $location ] = $menu_id;
		}
		$assigned_menu = get_nav_menu_locations();
		foreach ( $assigned_menu as $location => $term_id ) {
			if ( $term_id === $menu_id ) {
				unset( $assigned_menu[ $location ] );
			}
		}
		$new_assignments = array_merge( $assigned_menu, $new_locations );
		set_theme_mod( 'nav_menu_locations', $new_assignments );

		return true;
	}

	/**
	 * Retrieves the term's schema, conforming to JSON Schema.
	 *
	 * @since 5.9.0
	 *
	 * @return array Item schema data.
	 */
	public function get_item_schema() {
		if ( $this->schema ) {
			return $this->add_additional_fields_schema( $this->schema );
		}

		$schema = parent::get_item_schema();
		unset( $schema['properties']['count'], $schema['properties']['link'], $schema['properties']['taxonomy'] );

		$schema['properties']['locations'] = array(
			'description' => __( 'The locations assigned to the menu.' ),
			'type'        => 'array',
			'items'       => array(
				'type' => 'string',
			),
			'context'     => array( 'view', 'edit' ),
			'arg_options' => array(
				'validate_callback' => static function ( $locations, $request, $param ) {
					$valid = rest_validate_request_arg( $locations, $request, $param );

					if ( true !== $valid ) {
						return $valid;
					}

					$locations = rest_sanitize_request_arg( $locations, $request, $param );

					foreach ( $locations as $location ) {
						if ( ! array_key_exists( $location, get_registered_nav_menus() ) ) {
							return new WP_Error(
								'rest_invalid_menu_location',
								__( 'Invalid menu location.' ),
								array(
									'location' => $location,
								)
							);
						}
					}

					return true;
				},
			),
		);

		$schema['properties']['auto_add'] = array(
			'description' => __( 'Whether to automatically add top level pages to this menu.' ),
			'context'     => array( 'view', 'edit' ),
			'type'        => 'boolean',
		);

		$this->schema = $schema;

		return $this->add_additional_fields_schema( $this->schema );
	}
}