@Test
 public void getFromPrimitiveCollectionNull() {
   try {
     ContainerUtils.getFromPrimitiveCollection(null);
     fail("Should throw an NullPointerException");
   } catch (NullPointerException e) {
     assertTrue("Should throw an NullPointerException", e instanceof NullPointerException);
   }
 }
 @Test
 public void getFromPrimitiveCollectionDouble() {
   Container container =
       ContainerUtils.getFromPrimitiveCollection(Arrays.asList(new Double[] {1d, 2d, 3d}));
   assertNotNull(container);
   assertEquals(3, container.size());
   for (Object object : container.getItemIds()) {
     assertTrue(object instanceof Double);
   }
 }
 @Test
 public void getFromPrimitiveCollectionInteger() {
   Container container =
       ContainerUtils.getFromPrimitiveCollection(Arrays.asList(new Integer[] {1, 2, 3}));
   assertNotNull(container);
   assertEquals(3, container.size());
   for (Object object : container.getItemIds()) {
     assertTrue(object instanceof Integer);
   }
 }
 @Test
 public void getFromPrimitiveCollectionString() {
   Container container =
       ContainerUtils.getFromPrimitiveCollection(Arrays.asList(new String[] {"a", "b", "c"}));
   assertNotNull(container);
   assertEquals(3, container.size());
   for (Object object : container.getItemIds()) {
     assertTrue(object instanceof String);
   }
 }
 @Test
 public void getFromPrimitiveCollectionEmpty() {
   Container container = ContainerUtils.getFromPrimitiveCollection(Arrays.asList(new String[] {}));
   assertNotNull(container);
   assertEquals(0, container.size());
 }