public void TraverseTests()
{
var root = new BinaryTreeNode <int>(1, null);
var left = root.AddLeft(2); left.AddRight(5); left.AddLeft(4);
root.AddRight(3);
var inOrderArray = new int[] { 4, 2, 5, 1, 3 };
var preOrderArray = new int[] { 1, 2, 4, 5, 3 };
var postOrderArray = new int[] { 4, 5, 2, 3, 1 };
var idx = 0;
root.InOrderTraversal((value) => { Assert.AreEqual <int>(inOrderArray[idx], value); idx++; });
idx = 0;
root.PreOrderTraversal((value) => { Assert.AreEqual <int>(preOrderArray[idx], value); idx++; });
idx = 0;
root.PostOrderTraversal((value) => { Assert.AreEqual <int>(postOrderArray[idx], value); idx++; });
}