public void ElementChangedTest() { // Arrange short[,] array = new short[4, 4] { { 1, 1, 1, 4 }, { 1, 1, 1, 3 }, { 1, 1, 1, 2 }, { 4, 3, 2, 1 } }; SymmetricMatrix <short> matrix = new SymmetricMatrix <short>(array); List <string> receivedEvents = new List <string>(); // Act matrix.ElementChanged += delegate(object sender, ElementChangedEventArgs e) { receivedEvents.Add(e.Message); }; matrix.ChangeElement(0, 2, 5); // Assert Assert.AreEqual(2, receivedEvents.Count); Assert.AreEqual("Element [0, 2] changed to 5", receivedEvents[0]); Assert.AreEqual("Element [2, 0] changed to 5", receivedEvents[1]); }