public static void Main(string[] args)
{
Node currentNode = null;
Tree.Insert(ref currentNode, 10);
Tree.Insert(ref currentNode, 20);
Tree.Insert(ref currentNode, 15);
Tree.Insert(ref currentNode, 0);
Tree.Insert(ref currentNode, 5);
Console.WriteLine("contains tests:");
Console.WriteLine($"{Tree.Contains(currentNode, 10) == true} , 10 exists");
Console.WriteLine($"{Tree.Contains(currentNode, 4) == false} , 4 does not exist");
Console.WriteLine($"{Tree.Contains(currentNode, 20) == true} , 20 exists");
Console.WriteLine($"{Tree.Contains(currentNode, 0) == true} , 0 exists");
Console.WriteLine($"{Tree.Contains(currentNode, 100) == false} , 100 does not exist");
Console.WriteLine("find min tests:");
Console.WriteLine($"{Tree.FindMin(currentNode) == 0} , 0 is the minumim");
Console.WriteLine("find max tests:");
Console.WriteLine($"{Tree.FindMin(currentNode) == 20} , 20 is the maximum");
Console.WriteLine("level-order traversal - can be used for printing the tree:");
Tree.LevelOrder(currentNode);
Console.WriteLine();
Console.WriteLine("pre-order traversal");
Tree.PreOrder(currentNode);
Console.WriteLine();
Console.WriteLine("in-order traversal - can be used for sorting the tree:");
Tree.InOrder(currentNode);
Console.WriteLine();
Console.WriteLine("post-order traversal");
Tree.PostOrder(currentNode);
}