Sylius\Behat\Page\Admin\Order\ShowPageInterface::getItemQuantity PHP Method

    public function getItemQuantity($itemName);

 /**
  * @Then /^(its) quantity should be ([^"]+)$/
  */
 public function itemQuantityShouldBe($itemName, $quantity)
 {
     $itemQuantityOnPage = $this->showPage->getItemQuantity($itemName);
     Assert::eq($itemQuantityOnPage, $quantity, 'Item quantity is %s, but should be %s.');
 }