public void TestAddToEndSucceeds()
 {
     var timeline = new ItemPurchaseTimeline();
     timeline.AddToEnd(new Item(2009, TimeSpan.Zero));
     timeline.AddToEnd(new Item(2009, TimeSpan.Zero));
     timeline.AddToEnd(new Item(2009, new TimeSpan(10)));
     Assert.AreEqual(3, timeline.Count);
 }
 public void TestAddToEndExceptionsWithInvalidTime()
 {
     var timeline = new ItemPurchaseTimeline();
     timeline.AddToEnd(new Item(2009, new TimeSpan(10)));
     timeline.AddToEnd(new Item(2009, TimeSpan.Zero));
 }