private function buildSaleItemsLinesViews(Model\SaleInterface $sale)
    {
        if (!$sale->hasItems()) {
            return;
        }

        foreach ($sale->getItems() as $item) {
            // We don't need to test if null is returned as root items can't be private.
            $this->view->addItem($this->buildSaleItemLineView($item));
        }
    }