public class Node {
   private Node leftNode;   
   private Node rightNode;
   private int data;        

   public Node( int data, Node leftNode, Node rightNode ){ 
      this.data = data;              
      this.leftNode = leftNode;
      this.rightNode = rightNode;  
   }
   public Node getRightNodeReference(){
      return this.rightNode;
   }
   public Node getLeftNodeReference(){
      return this.leftNode;
   }
   public void  setRightNodeReference(Node rightNode){
       this.rightNode = rightNode;
   }
   public void setLeftNodeReference(Node leftNode){
      this.leftNode = leftNode;
   }
   public int getData(){
      return this.data;
   }
}