@Test
 public void testAdd() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   int size = subject.size();
   Assert.assertEquals(7, size);
 }
 @Test
 public void testToArray() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   int size = subject.size();
   Assert.assertEquals(7, size);
   Object[] animals = subject.toArray();
   Assert.assertEquals(7, animals.length);
 }
 @Test
 public void testPeek() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   int size = subject.size();
   Assert.assertEquals(7, size);
   String animal = subject.peek();
   Assert.assertEquals("cows", animal);
   size = subject.size();
   Assert.assertEquals(7, size);
 }
 @Test
 public void testPoll() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   int size = subject.size();
   Assert.assertEquals(7, size);
   String animal = subject.poll();
   Assert.assertEquals("cows", animal);
   size = subject.size();
   Assert.assertEquals(6, size);
   animal = subject.poll();
   Assert.assertEquals("sheep", animal);
   size = subject.size();
   Assert.assertEquals(5, size);
   animal = subject.poll();
   Assert.assertEquals("ducks", animal);
   size = subject.size();
   Assert.assertEquals(4, size);
   animal = subject.poll();
   Assert.assertEquals("mice", animal);
   size = subject.size();
   Assert.assertEquals(3, size);
   animal = subject.poll();
   Assert.assertEquals("dogs", animal);
   size = subject.size();
   Assert.assertEquals(2, size);
   animal = subject.poll();
   Assert.assertEquals("cats", animal);
   size = subject.size();
   Assert.assertEquals(1, size);
   animal = subject.poll();
   Assert.assertEquals("birds", animal);
   size = subject.size();
   Assert.assertEquals(0, size);
   animal = subject.poll();
   Assert.assertEquals(null, animal);
 }
 @Test(expected = NoSuchElementException.class)
 public void testRemove() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   int size = subject.size();
   Assert.assertEquals(7, size);
   String animal = subject.remove();
   Assert.assertEquals("cows", animal);
   size = subject.size();
   Assert.assertEquals(6, size);
   animal = subject.remove();
   Assert.assertEquals("sheep", animal);
   size = subject.size();
   Assert.assertEquals(5, size);
   animal = subject.remove();
   Assert.assertEquals("ducks", animal);
   size = subject.size();
   Assert.assertEquals(4, size);
   animal = subject.remove();
   Assert.assertEquals("mice", animal);
   size = subject.size();
   Assert.assertEquals(3, size);
   animal = subject.remove();
   Assert.assertEquals("dogs", animal);
   size = subject.size();
   Assert.assertEquals(2, size);
   animal = subject.remove();
   Assert.assertEquals("cats", animal);
   size = subject.size();
   Assert.assertEquals(1, size);
   animal = subject.remove();
   Assert.assertEquals("birds", animal);
   size = subject.size();
   Assert.assertEquals(0, size);
   animal = subject.remove();
 }
 @Test
 public void testEmpty() throws Exception {
   subject.add("cows");
   subject.add("sheep");
   subject.add("ducks");
   subject.add("mice");
   subject.add("dogs");
   subject.add("cats");
   subject.add("birds");
   subject.clear();
   boolean nothing = subject.isEmpty();
   Assert.assertTrue(nothing);
   subject.add("birds");
   nothing = subject.isEmpty();
   Assert.assertFalse(nothing);
 }