Dumplie\Customer\Application\Exception\QueryException::cartNotFound PHP Method

    public static function cartNotFound($cartId) : QueryException
    {
        return new self(sprintf("Cart with id \"%s\" does not exists.", $cartId));
    }

 /**
  * @param string $cartId
  *
  * @throws QueryException
  * @return Cart
  */
 public function getById(string $cartId) : Cart
 {
     $qb = $this->connection->createQueryBuilder();
     $qb->select('id', 'currency', 'cart_items')->from('dumplie_customer_cart')->where('id = :id')->setParameter('id', $cartId);
     $cartData = $this->connection->fetchAssoc($qb->getSQL(), $qb->getParameters());
     if (empty($cartData)) {
         throw QueryException::cartNotFound($cartId);
     }
     $itemsData = json_decode($cartData['cart_items'], true);
     $items = [];
     foreach ($itemsData as $item) {
         $items[] = $this->getItemBySku($item['sku'], $item['quantity']);
     }
     return new Cart($cartData['currency'], $items);
 }