WordPress Version: 5.9
/**
* Adds the sidebar toggle button.
*
* @since 3.8.0
*
* @param WP_Admin_Bar $wp_admin_bar The WP_Admin_Bar instance.
*/
function wp_admin_bar_sidebar_toggle($wp_admin_bar)
{
if (is_admin()) {
$wp_admin_bar->add_node(array('id' => 'menu-toggle', 'title' => '<span class="ab-icon" aria-hidden="true"></span><span class="screen-reader-text">' . __('Menu') . '</span>', 'href' => '#'));
}
}