public static void TestCalcLevelAllNodes()
{
var root = new SimpleTreeNode <int>(1, null);
var tree = new SimpleTree <int>(root);
var node = new SimpleTreeNode <int>(2, root);
tree.AddChild(root, node);
var node3 = new SimpleTreeNode <int>(3, root);
tree.AddChild(root, node3);
var node4 = new SimpleTreeNode <int>(4, node3);
tree.AddChild(node3, node4);
tree.CalcLevelAllNodes();
Assert.AreEqual(1, root.Level);
Assert.AreEqual(2, node.Level);
Assert.AreEqual(2, node3.Level);
Assert.AreEqual(3, node4.Level);
}