public void NotDelayed_ReturnsFalse()
            {
                var shipment = new ShipmentBuilder()
                               .EstimatedArrivalDate(DateTime.Today.AddDays(1))
                               .Build();

                Assert.That(shipment.IsDelayedMoreThan7Days(), Is.False);
            }
            public void DelayedButDelivered_ReturnsFalse()
            {
                var shipment = new ShipmentBuilder()
                               .EstimatedArrivalDate(DateTime.Today.AddDays(-8))
                               .Build();

                shipment.UpdateStatus(ShipmentStatus.Trigger.Shipped);
                shipment.UpdateStatus(ShipmentStatus.Trigger.Delivered);

                Assert.That(shipment.IsDelayedMoreThan7Days(), Is.False);
            }