@Test public void test2_addfirst() throws Exception { // Given list.add(1); list.add(2); // When list.addFirst(3); // Then int got = list.get(0); Assert.assertEquals(3, got); Assert.assertEquals(1, (int) list.get(1)); Assert.assertEquals(2, (int) list.get(2)); System.out.println(list); // extra for (int i = 0; i < list.size(); i++) { System.out.println(list.get(i)); } }