public void AddRangeTest()
        {
            int didNotify = 0;
            MTObservableCollection <string> coll = new MTObservableCollection <string>();

            coll.CollectionChanged += (s, e) => didNotify++;

            coll.AddRange(new[] { "One", "Two", "Three", "Four" });
            Assert.AreEqual(4, coll.Count);
            Assert.AreEqual(1, didNotify);
        }