public void NullLocArrivalTest()
        {
            var layover = new Layover(1, "2019-01-01", "2019-01-02", 2000, 1, 0);

            Assert.Throws <InvalidAttributeException>(() => layover.Validate());
        }
        public void EmptyArrivalDateTest()
        {
            var layover = new Layover(1, "2019-01-01", "", 2000, 0, 2);

            Assert.Throws <InvalidAttributeException>(() => layover.Validate());
        }