Order/EventListener/OrderListener.php
protected function updateVatDisplayMode(SaleInterface $sale)
    {
        // Vat display mode must not change if order has shipments or invoices.
        if ($sale->hasShipments() || $sale->hasInvoices()) {
            return false;
        }

        return parent::updateVatDisplayMode($sale);
    }
protected function updateVatDisplayMode(SaleInterface $sale)
    {
        // Vat display mode must not change if order has shipments or invoices.
        if ($sale->hasShipments() || $sale->hasInvoices()) {
            return false;
        }

        return parent::updateVatDisplayMode($sale);
    }
@inheritDoc

@param OrderInterface $sale