wp-includes/admin-bar.php:240Adds the sidebar toggle button.
$wp_admin_barWP_Admin_Barfunction 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">' . /* translators: Hidden accessibility text. */ __( 'Menu' ) . '</span>', 'href' => '#', ) ); }}Introduced in 3.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/admin-bar.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.