function get_menu($menu_name) {
  $menu_tree = Drupal::menuTree();
  $parameters = $menu_tree->getCurrentRouteMenuTreeParameters($menu_name);
  $tree = $menu_tree->load($menu_name, $parameters);
  $manipulators = array(
    // Only show links that are accessible for the current user.
    array('callable' => 'menu.default_tree_manipulators:checkAccess'),
    // Use the default sorting of menu links.
    array('callable' => 'menu.default_tree_manipulators:generateIndexAndSort'),
  );
  $tree = $menu_tree->transform($tree, $manipulators);
  $menu = $menu_tree->build($tree);

  return array('#markup' => drupal_render($menu));
}