public function renderAction()
{
    $this->get('some_service')->render();
    $someService = $this->get('some_service');
}

/** 
 * @var SomeService
 */
private $someService;

public function __construct(SomeService $someService)
{
    $this->someService = $someService;
}

public function renderAction()
{
    $this->someService->render();
    $someService = $this->someService;
}