assertEquals(1,it.previousIndex());
assertEquals(2,it.nextIndex());
assertEquals("2",it.previous());
assertTrue(it.hasNext());
assertTrue(it.hasPrevious());
assertEquals(0,it.previousIndex());
assertEquals(1,it.nextIndex());
assertEquals("1",it.previous());
assertTrue(it.hasNext());
assertTrue(!it.hasPrevious());
assertEquals(-1,it.previousIndex());