public class Node {

    // A very simple class for linked list nodes
    // Not polymorphic, these nodes are restricted to ints
    // We will just use null for empty lists.

    // Instance variables for two fields
    protected int data;
    protected Node next;

    // Constructor
    public Node(int d, Node n) {
        data = d;
        next = n;
    }

    // These nodes are immutable.  we provide only accessor methods:
    public int getData() {
        return data;
    }
    public Node getNext() {
        return next;
    }
}