public void TravInTest()
{
BinTree<int> tree = new BinTree<int>(new BinNode<int>(10));
tree.InsertAsLC(tree.Root(), 15);
tree.InsertAsLC(tree.Root().LChild, 16);
tree.InsertAsRC(tree.Root().LChild, 17);
tree.InsertAsRC(tree.Root(), 20);
tree.InsertAsLC(tree.Root().RChild, 21);
int sum = 0;
tree.TravIn(o => sum += o);
Assert.IsTrue(sum == 99);
}