public void addGuestTest2()
{
OrderServer.addGuest("", "", "", 0);
List <Order> Inf2 = new List <Order>()
{
new Order("001", "A", "a", 11000),
new Order("002", "B", "b", 9000),
new Order("003", "C", "c", 15000),
new Order("", "", "", 0)
};
Assert.AreEqual(Inf2, Inf2);
}