Instructions for migrate legacy Knp-Menu code to version 2.0 - symfony

Question

I need to migrate a really old version of Knp Menu to a newest one. The real problem is here
$collapse = new CollapseItem($group,$router->generate('seguridad_group_list'),array('class'=>'submenu'),'Primicia\SeguridadBundle\Menu\CollapseItem');
$collapse->setIcon('sp sp-ico-menu-grupo sp-icon-display');
$this->addChild($collapse);
How can I make it following the menu-as-service-way in the version 2 of KnpMenu?
The rest of code is this
The menu service implementation:
namespace Primicia\SeguridadBundle\Menu;
use Knp\Bundle\MenuBundle\Menu;
use Symfony\Component\DependencyInjection\Container;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Routing\Router;
use Knp\Bundle\MenuBundle\Renderer\RendererInterface;
class SeguridadMenu extends Menu {
/**
* #param Request $request
* #param Router $router
* #param Container $container
*/
public function __construct(Request $request, Router $router, $container)
{
parent::__construct();
$this->setCurrentUri($request->getRequestUri());
$this->setAttribute('class','nav nav-list menu_lateral');
$translator = $container->get('translator');
if($container->get('security.context')->isGranted('ROLE_ADMIN'))
{
$user = $translator->trans('menu.user.titles',array(),'SeguridadBundle');
$signal = new CollapseItem($user,$router->generate('seguridad_user_list'),array('class'=>'submenu'),'Primicia\SeguridadBundle\Menu\CollapseItem');
$signal->setIcon('sp sp-ico-menu-usuario sp-icon-display');
$this->addChild($signal);
$group = $translator->trans('menu.group.titles',array(),'SeguridadBundle');
$collapse = new CollapseItem($group,$router->generate('seguridad_group_list'),array('class'=>'submenu'),'Primicia\SeguridadBundle\Menu\CollapseItem');
$collapse->setIcon('sp sp-ico-menu-grupo sp-icon-display');
$this->addChild($collapse);
}
}
/**
* Gets renderer which is used to render menu items.
*
* #return RendererInterface $renderer Renderer.
*/
public function getRenderer()
{
if(null === $this->renderer) {
if($this->isRoot()) {
$this->setRenderer(new ApcRenderer());
}
else {
return $this->getParent()->getRenderer();
}
}
return $this->renderer;
}
}
The CollapseItem class, which is used in the $router->generate
namespace Primicia\SeguridadBundle\Menu;
use Knp\Menu\MenuItem;
class CollapseItem extends MenuItem
{
protected $hasIcon;
public function renderLink()
{
$label = $this->renderLabel();
$uri = $this->getUri();
if (!$uri) {
die;
return sprintf('<a class="dropdown-toggle" href="#">%s</a>', $label);
}
return sprintf('<a class="dropdown-toggle" href="%s">%s</a>', $uri, $label);
}
public function setIcon($icon)
{
$this->hasIcon=$icon;
return $this;
}
public function getIcon()
{
return $this->hasIcon;
}
}