Order/EventListener/OrderItemListener.php
protected function getSaleItemFromEvent(ResourceEventInterface $event)
    {
        $item = $event->getResource();

        if (!$item instanceof OrderItemInterface) {
            throw new InvalidArgumentException("Expected instance of OrderItemInterface");
        }

        return $item;
    }
protected function getSaleItemFromEvent(ResourceEventInterface $event)
    {
        $item = $event->getResource();

        if (!$item instanceof OrderItemInterface) {
            throw new InvalidArgumentException("Expected instance of OrderItemInterface");
        }

        return $item;
    }
protected function getSaleItemFromEvent ( ResourceEventInterface $ event ) { $ item = $ event -> getResource ( ) ; if ( ! $ item instanceof OrderItemInterface ) { throw new InvalidArgumentException ( "Expected instance of OrderItemInterface" ) ; } return $ item ; }
@inheritdoc

@return OrderItemInterface
@inheritdoc