public function testCreateCategoryMenu()
{
$menu = $this->getMock('Knp\\Menu\\ItemInterface');
$factory = $this->getMock('Knp\\Menu\\FactoryInterface');
$factory->expects($this->once())->method('createItem')->will($this->returnValue($menu));
$categoryManager = $this->getMock('Sonata\\Component\\Product\\ProductCategoryManagerInterface');
$router = $this->getMock('Symfony\\Component\\Routing\\RouterInterface');
$categoryManager->expects($this->once())->method('getCategoryTree')->will($this->returnValue(array()));
$builder = new ProductMenuBuilder($factory, $categoryManager, $router);
$genMenu = $builder->createCategoryMenu();
$this->assertInstanceOf('Knp\\Menu\\ItemInterface', $genMenu);
}