t

public void testAddNewNode() {
        String[] items = {"b","c","e"};
        ArrayList<DNode> list = createList(items);
        DNode head = list.get(0);

        DLSList testList= new DLSList();
        testList.head= head;
        testList.numNodes= items.length;
        testList.lastVisited= testList.head; // Initialise testList to satisfy the class invariant

        // now prepare and add a node
        DNode nodeToAdd= new DNode("d");
        testList.addNewNode(nodeToAdd);

        String testArray1[]= {"b", "c", "d", "e" };

        DNode temp= testList.head;
        for(int i=0; i< testArray1.length; i++){ // Checks the order of nodes starting from the first node
            assertEquals(testArray1[i], temp.contents);
            temp=temp.next;
        }
        assertEquals(testArray1.length, testList.numNodes);

        nodeToAdd= new DNode("f");
        testList.addNewNode(nodeToAdd);

        String testArray2[]= {"b", "c", "d", "e", "f" };
        temp = testList.head;
        for(int i=0; i< testArray2.length; i++){
            assertEquals(testArray2[i], temp.contents);
            temp=temp.next;
        }
        assertEquals(testArray2.length, testList.numNodes);

        nodeToAdd= new DNode("a");
        testList.addNewNode(nodeToAdd);

        String testArray3[]= {"a", "b", "c", "d", "e", "f" };
        temp = testList.head;
        for(int i=0; i< testArray3.length; i++){
            assertEquals(testArray3[i], temp.contents);
            temp=temp.next;
        }
        assertEquals(testArray3.length, testList.numNodes);
    }