public void CopyItems()
{
var tree = new TTree <int>(2, 2);
tree.Add(10);
tree.Add(11);
tree.Add(1);
tree.Add(20);
var items = new int[20];
tree.CopyItems(items, 0);
Assert.AreEqual(1, items[0], "Invalid value at 0");
Assert.AreEqual(10, items[1], "Invalid value at 1");
Assert.AreEqual(11, items[2], "Invalid value at 2");
Assert.AreEqual(20, items[3], "Invalid value at 3");
}