// Similar to the Node class we used for a linked list,
// except for the pointers that we need:  2 children and a parent.
public class Node
{
  protected Node left;
  protected Node right;
  protected Node parent;
  protected Item data;

  public Node(Item value)
  {
    left = null;
    right = null;
    parent = null;
    data = value;
  }

  public Item getData()
  {
    return data;
  }
}