Order/EventListener/OrderListener.php
protected function applySaleItemRecursively(SaleItemInterface $item)
    {
        $this->stockAssigner->applySaleItem($item);

        foreach ($item->getChildren() as $child) {
            $this->applySaleItemRecursively($child);
        }
    }
protected function applySaleItemRecursively(SaleItemInterface $item)
    {
        $this->stockAssigner->applySaleItem($item);

        foreach ($item->getChildren() as $child) {
            $this->applySaleItemRecursively($child);
        }
    }
Applies the sale item to stock units recursively.

@param SaleItemInterface $item