Sylius\Behat\Page\Shop\Product\ShowPageInterface::addToCartWithQuantity PHP Method

    public function addToCartWithQuantity($quantity);

 /**
  * @Given /^I have(?:| added) (\d+) (products "([^"]+)") (?:to|in) the cart$/
  * @When /^I add(?:|ed)(?:| again) (\d+) (products "([^"]+)") to the cart$/
  */
 public function iAddProductsToTheCart($quantity, ProductInterface $product)
 {
     $this->productShowPage->open(['slug' => $product->getSlug()]);
     $this->productShowPage->addToCartWithQuantity($quantity);
     $this->sharedStorage->set('product', $product);
 }