public void SizeTest()
{
BinarySearchTree<int> bst = ConstructTree(5,4,8);
Assert.AreEqual(3, bst.Size(bst.RootNode));
bst = ConstructTree(5);
Assert.AreEqual(1, bst.Size(bst.RootNode));
bst = new BinarySearchTree<int>();
Assert.AreEqual(0, bst.Size(bst.RootNode));
}