public void IsOrderByDescending()
        {
            var customers = new List<Customer>
            {
                new Customer { Id = 3 },
                new Customer { Id = 2 },
                new Customer { Id = 1 }
            };

            Assert.False(customers.IsOrderedByAscending(x => x.Id));
        }
        public void TestOrderByAscending()
        {
            var customers = new List<Customer>
            {
                new Customer { Id = 3 },
                new Customer { Id = 2 },
                new Customer { Id = 1 }
            };

            customers = customers.OrderBy(x => x.Id).ToList();

            Assert.True(customers.IsOrderedByAscending(x => x.Id));
        }