private static void testAfterInsertEnd() {
    SList lst1 = new SList();
    lst1.insertEnd(new Integer(6));
    lst1.insertEnd(new Integer(7));
    System.out.println();
    System.out.println("Here is a list after insertEnd 6, 7: "
               + lst1.toString());
    System.out.println("isEmpty() should be false. It is: " +
               lst1.isEmpty());
    TestHelper.verify(lst1.isEmpty() == false,
              "isEmpty() after insertEnd failed");
    System.out.println("length() should be 2. It is: " +
               lst1.length());
    TestHelper.verify(lst1.length() == 2,
              "length() after insertEndfailed");
    lst1.insertFront(new Integer(5));
    System.out.println("Here is the same list after insertFront(5): "
               + lst1.toString());
    TestHelper.verify(lst1.toString().equals("[  5  6  7  ]"),
              "insertFront after insertEnd failed");
  }
}