public class LinkedList<E> {
    // the first element of this LinkedList
    private Node start;

    // the last element of this LinkedList
    private Node end;

    // the number of elements that constitute this LinkedList
    private int length;

    private class Node {
        private Node last;
        private Node next;

        private E data;

        // each Node has a reference to the previous Node and
        // the next Node. The first element of the LinkedList
        // will have a null reference to the previous element
        // and the last element will have a null reference to
        // the next element. Each Node stores a piece of data
        // in the data variable.
    }

    public void clear() {
        start = null;
        end = null;

        length = 0;
    }

    // other methods omitted
}

LinkedList
    |   |

Node1  Node2