public void Test_CopyTo()
{
var coll = new SortedObservableCollection <int> {
3, 1, 2, 5, 4
};
var arr = new int[8] {
7, 7, 7, 7, 7, 7, 7, 7
};
coll.CopyTo(arr, 2);
CollectionAssert.AreEqual(new int[] { 7, 7, 1, 2, 3, 4, 5, 7 }, arr);
}