WP_Customize_New_Menu_Section

class WP_Customize_New_Menu_Section extends WP_Customize_Section {

	/**
	 * Control type.
	 *
	 * @since WP-4.3.0
	 * @var string
	 */
	public $type = 'new_menu';

	/**
	 * Constructor.
	 *
	 * Any supplied $args override class property defaults.
	 *
	 * @since WP-4.9.0
	 *
	 * @param WP_Customize_Manager $manager Customizer bootstrap instance.
	 * @param string               $id      An specific ID of the section.
	 * @param array                $args    Section arguments.
	 */
	public function __construct( WP_Customize_Manager $manager, $id, array $args = array() ) {
		_deprecated_file( basename( __FILE__ ), 'WP-4.9.0' ); // @todo Move this outside of class in WP-5.0, and remove its require_once() from class-wp-customize-section.php. See https://core.trac.wordpress.org/ticket/42364.
		parent::__construct( $manager, $id, $args );
	}

	/**
	 * Render the section, and the controls that have been added to it.
	 *
	 * @since WP-4.3.0
	 */
	protected function render() {
		?>
		<li id="accordion-section-<?php echo esc_attr( $this->id ); ?>" class="accordion-section-new-menu">
			<button type="button" class="button add-new-menu-item add-menu-toggle" aria-expanded="false">
				<?php echo esc_html( $this->title ); ?>
			</button>
			<ul class="new-menu-section-content"></ul>
		</li>
		<?php
	}
}