}
		}
	} // Success.
	return nil
}

func getValidPath(path string) (string, error) {
	if path == "" {
		return path, errInvalidArgument
	}

	var err error
	// Disallow relative paths, figure out absolute paths.
	path, err = filepath.Abs(path)
	if err != nil {
		return path, err
	}

	fi, err := Lstat(path)
	if err != nil && !osIsNotExist(err) {
		return path, err
	}

    return (UnmodifiableListIterator<T>) ArrayItr.EMPTY;
  }

  /**
   * This is an enum singleton rather than an anonymous class so ProGuard can figure out it's only
   * referenced by emptyModifiableIterator().
   */
  private enum EmptyModifiableIterator implements Iterator<Object> {
    INSTANCE;

    @Override
    public boolean hasNext() {

    assertEquals("b", consumingIterator.next());
    assertThat(list).isEmpty();

    assertFalse(consumingIterator.hasNext());
  }

  @GwtIncompatible // ?
  // TODO: Figure out why this is failing in GWT.
  public void testConsumingIterator_duelingIterators() {
    // Test data
    List<String> list = Lists.newArrayList("a", "b");

    // Test & Verify

    assertEquals("b", consumingIterator.next());
    assertThat(list).isEmpty();

    assertFalse(consumingIterator.hasNext());
  }

  @GwtIncompatible // ?
  // TODO: Figure out why this is failing in GWT.
  public void testConsumingIterator_duelingIterators() {
    // Test data
    List<String> list = Lists.newArrayList("a", "b");

    // Test & Verify

// ServerAddressByClientCIDR helps the client to determine the server address that they should use, depending on the clientCIDR that they match.
message ServerAddressByClientCIDR {
  // The CIDR with which clients can match their IP to figure out the server address that they should use.
  optional string clientCIDR = 1;

  // Address of this server, suitable for a client that matches the above CIDR.
  // This can be a hostname, hostname:port, IP or IP:port.

          // misconfigured mock. Try to switch to Failure.
          Failure failure;
          try {
            failure = new Failure(t);
          } catch (Exception | Error oomMostLikely) { // sneaky checked exception
            failure = Failure.FALLBACK_INSTANCE;
          }

  }

  void assertThatFutureFailsWithException(Future<?> future) {
    try {
      getUninterruptibly(future);
      fail("Expected future to fail: " + future);
    } catch (ExecutionException e) {
      assertThat(e).hasCauseThat().isSameInstanceAs(exception);
    }
  }

  static void assertThatFutureBecomesCancelled(Future<?> future) throws ExecutionException {
    try {

    final Future<V> future;
    final FutureCallback<? super V> callback;

    CallbackListener(Future<V> future, FutureCallback<? super V> callback) {
      this.future = future;
      this.callback = callback;
    }

    @Override
    public void run() {
      if (future instanceof InternalFutureFailureAccess) {
        Throwable failure =

  }

  void assertThatFutureFailsWithException(Future<?> future) {
    try {
      getUninterruptibly(future);
      fail("Expected future to fail: " + future);
    } catch (ExecutionException e) {
      assertThat(e).hasCauseThat().isSameInstanceAs(exception);
    }
  }

  static void assertThatFutureBecomesCancelled(Future<?> future) throws ExecutionException {
    try {

                    .collect(Collectors.toList());
            try {
                List<Future<InterimResult>> futures = executor.invokeAll(tasks);
                List<InterimResult> list = new ArrayList<>();
                for (Future<InterimResult> future : futures) {
                    InterimResult interimResult = future.get();
                    list.add(interimResult);
                }
                return list;