Common/Listener/ShipmentNotifyListener.php
protected function hasNotification(SaleInterface $sale, $type, $number)
    {
        foreach ($sale->getNotifications() as $n) {
            if ($n->getType() !== $type) {
                continue;
            }

            if ($n->hasData('shipment') && $n->getData('shipment') === $number) {
                return true;
            }
        }

        return false;
    }
protected function hasNotification(SaleInterface $sale, $type, $number)
    {
        foreach ($sale->getNotifications() as $n) {
            if ($n->getType() !== $type) {
                continue;
            }

            if ($n->hasData('shipment') && $n->getData('shipment') === $number) {
                return true;
            }
        }

        return false;
    }
Returns whether the sae has a notification with the given type and shipment number.

@param SaleInterface $sale
@param               $type
@param               $number

@return bool