private final ForwardingWrapperTester tester = new ForwardingWrapperTester();

  public void testGoodForwarder() {
    tester.testForwarding(
        Arithmetic.class,
        new Function<Arithmetic, Arithmetic>() {
          @Override
          public Arithmetic apply(Arithmetic arithmetic) {
            return new ForwardingArithmetic(arithmetic);
          }
        });
    tester.testForwarding(

    class BadRunnableException extends RuntimeException {}

    CountingRunnable before = new CountingRunnable();
    Runnable bad =
        new Runnable() {
          @Override
          public void run() {
            throw new BadRunnableException();
          }
        };
    CountingRunnable after = new CountingRunnable();

    future.addListener(before, directExecutor());

    List<Object> list = new ArrayList<>();
    Helpers.assertEmpty(list);
    Helpers.assertEmpty(
        new Iterable<Object>() {
          @Override
          public Iterator<Object> iterator() {
            return Collections.emptyList().iterator();
          }
        });

    list.add("a");
    try {
      Helpers.assertEmpty(list);
      throw new Error();

        .add(new Striped.LargeLazyStriped<ReadWriteLock>(50, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.LargeLazyStriped<ReadWriteLock>(64, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.SmallLazyStriped<Lock>(50, LOCK_SUPPLER))
        .add(new Striped.SmallLazyStriped<Lock>(64, LOCK_SUPPLER))
        .add(new Striped.LargeLazyStriped<Lock>(50, LOCK_SUPPLER))
        .add(new Striped.LargeLazyStriped<Lock>(64, LOCK_SUPPLER))

    testSortDescending(new byte[] {}, 0, 0, new byte[] {});
    testSortDescending(new byte[] {1}, 0, 1, new byte[] {1});
    testSortDescending(new byte[] {1, 2}, 0, 2, new byte[] {2, 1});
    testSortDescending(new byte[] {1, 3, 1}, 0, 2, new byte[] {3, 1, 1});
    testSortDescending(new byte[] {1, 3, 1}, 0, 1, new byte[] {1, 3, 1});
    testSortDescending(new byte[] {-1, -2, 1, 2}, 1, 3, new byte[] {-1, 1, -2, 2});
  }

    HashCode expectedHash = Hashing.md5().hashBytes(new byte[] {'m', 's'});
    HashingInputStream in = new HashingInputStream(Hashing.md5(), buffer);

    long numOfByteSkipped = in.skip(2);
    assertEquals(2, numOfByteSkipped);

    byte[] buf = new byte[4];
    int numOfByteRead = in.read(buf, 0, buf.length);
    assertEquals(2, numOfByteRead);

    assertEquals(expectedHash, in.hash());
  }

  final TestCloseable closeable1 = new TestCloseable("closeable1");
  final TestCloseable closeable2 = new TestCloseable("closeable2");
  final TestCloseable closeable3 = new TestCloseable("closeable3");
  final TestCloseable closeable4 = new TestCloseable("closeable4");

  final Waiter waiter = new Waiter();
  final CountDownLatch futureCancelled = new CountDownLatch(1);
  final Exception exception = new Exception();

  public static Test suite() {
    TestSuite suite = new TestSuite();

    suite.addTest(
        NavigableMapTestSuiteBuilder.using(
                new TestStringSortedMapGenerator() {
                  @Override
                  protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                    SafeTreeMap<String, String> map = new SafeTreeMap<>();
                    putEntries(map, entries);

    Object unused1 = new Object() {};
    Object unused2 = new Object() {};
    Object unused3 = new Object() {};
    Object unused4 = new Object() {};
    Object unused5 = new Object() {};
    Object unused6 = new Object() {};
    Object unused7 = new Object() {};
    Object unused8 = new Object() {};
    Object unused9 = new Object() {};
    Object o10 = new Object() {};

    AbstractService service = new DefaultService();
    assertThrows(IllegalStateException.class, () -> service.notifyFailed(new Exception()));
  }

  public void testNotifyFailedWhenTerminated() {
    NoOpService service = new NoOpService();
    service.startAsync().awaitRunning();
    service.stopAsync().awaitTerminated();
    assertThrows(IllegalStateException.class, () -> service.notifyFailed(new Exception()));
  }