public void DeleteDrinkTest()
{
Assert.AreEqual(_orderList.GetDrinkCount(), 0);
_orderList.DeleteDrink(0);
Assert.AreEqual(_orderList.GetDrinkCount(), 0);
_orderList.OrderDrink(new Drink("D", 110));
Assert.AreEqual(_orderList.GetDrinkCount(), 1);
_orderList.DeleteDrink(-1);
Assert.AreEqual(_orderList.GetDrinkCount(), 1);
_orderList.DeleteDrink(1);
Assert.AreEqual(_orderList.GetDrinkCount(), 1);
_orderList.DeleteDrink(0);
Assert.AreEqual(_orderList.GetDrinkCount(), 0);
}