public void updateStockTest(
     [PexAssumeUnderTest] ProductStock target,
     int id,
     int newStock
     )
 {
     target.updateStock(id, newStock);
     // TODO: add assertions to method ProductStockTest.updateStockTest(ProductStock, Int32, Int32)
 }
        public void updateStock_Test(int id, int stock, int expected)
        {
            var result = itemsInStock.updateStock(id, stock);

            Assert.AreEqual(result, expected);
        }