WP_Customize_Nav_Menu_Setting example

    /** * Enqueues scripts and styles for Customizer pane. * * @since 4.3.0 */
    public function enqueue_scripts() {
        wp_enqueue_style( 'customize-nav-menus' );
        wp_enqueue_script( 'customize-nav-menus' );

        $temp_nav_menu_setting      = new WP_Customize_Nav_Menu_Setting( $this->manager, 'nav_menu[-1]' );
        $temp_nav_menu_item_setting = new WP_Customize_Nav_Menu_Item_Setting( $this->manager, 'nav_menu_item[-1]' );

        $num_locations = count( get_registered_nav_menus() );

        if ( 1 === $num_locations ) {
            $locations_description = __( 'Your theme can display menus in one location.' );
        } else {
            /* translators: %s: Number of menu locations. */
            $locations_description = sprintf( _n( 'Your theme can display menus in %s location.', 'Your theme can display menus in %s locations.', $num_locations ), number_format_i18n( $num_locations ) );
        }