WP nav menu + Bootstrap, add role=”menu” to UL

[Update] Solution found:

I was looking for 'items_wrap' => '<ul id="%1$s" class="%2$s" role="menu" >%3$s</ul>'

    <?php
        wp_nav_menu( array(
            'menu'              => 'menu',
            'theme_location'    => 'menu',
            'items_wrap' => '<ul id="%1$s" class="%2$s" role="menu" >%3$s</ul>',
            'depth'             => 0,
            'container'         => '',
            'menu_class'        => 'dropdown-menu',
            'fallback_cb'       => 'wp_bootstrap_navwalker::fallback',
            'walker'            => new wp_bootstrap_navwalker())
        );
    ?>