@Test
public void testAddToTail() {
IntegerList list = new IntegerList(5);
list.addToTail(6);
assertEquals(6, list.getTailValue());
assertEquals(5, list.getHeadValue());
}
@Test
public void testGetTailValue() {
IntegerList list = new IntegerList(5);
list.addToTail(6);
list.addToTail(7);
assertEquals(7, list.getTailValue());
}