}

  public void testToStringWithNull() {
    Iterator<@Nullable String> iterator =
        Lists.<@Nullable String>newArrayList("hello", null, "world").iterator();
    assertEquals("[hello, null, world]", Iterators.toString(iterator));
  }

  public void testToStringEmptyIterator() {
    Iterator<String> iterator = Collections.<String>emptyList().iterator();

  }

  @SuppressWarnings("serial")
  public void testLinkedHashMapWithInitialMap() {
    Map<String, String> map =
        new LinkedHashMap<String, String>(
            ImmutableMap.of(
                "Hello", "World",
                "first", "second",
                "polygene", "lubricants",
                "alpha", "betical"));

    LinkedHashMap<String, String> copy = Maps.newLinkedHashMap(map);

  }

  @SuppressWarnings("serial")
  public void testLinkedHashMapWithInitialMap() {
    Map<String, String> map =
        new LinkedHashMap<String, String>(
            ImmutableMap.of(
                "Hello", "World",
                "first", "second",
                "polygene", "lubricants",
                "alpha", "betical"));

    LinkedHashMap<String, String> copy = Maps.newLinkedHashMap(map);

  }

  public void testToStringWithNull() {
    Iterator<@Nullable String> iterator =
        Lists.<@Nullable String>newArrayList("hello", null, "world").iterator();
    assertEquals("[hello, null, world]", Iterators.toString(iterator));
  }

  public void testToStringEmptyIterator() {
    Iterator<String> iterator = Collections.<String>emptyList().iterator();