* returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong plus(UnsignedLong val) {
    return fromLongBits(this.value + checkNotNull(val).value);
  }

  /**
   * Returns the result of subtracting this and {@code val}. If the result would have more than 64
   * bits, returns the low 64 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedLong minus(UnsignedLong val) {

   * returns the low 32 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedInteger plus(UnsignedInteger val) {
    return fromIntBits(this.value + checkNotNull(val).value);
  }

  /**
   * Returns the result of subtracting this and {@code val}. If the result would be negative,
   * returns the low 32 bits of the result.
   *
   * @since 14.0
   */
  public UnsignedInteger minus(UnsignedInteger val) {

		return
	}
	xls := xlStorage{drivePath: base, diskInfoCache: cachevalue.New[DiskInfo]()}
	xls.diskInfoCache.InitOnce(time.Second, cachevalue.Opts{}, func(ctx context.Context) (DiskInfo, error) {
		return DiskInfo{Total: 1 << 40, Free: 1 << 40}, nil
	})
	weSleep := func() bool { return false }

	got, err := scanDataFolder(t.Context(), nil, &xls, dataUsageCache{Info: dataUsageCacheInfo{Name: bucket}}, getSize, 0, weSleep)
	if err != nil {
		t.Fatal(err)

   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#flatMap} (using a function that produces
   * streams, not iterables).
   *
   * @since 13.0 (required {@code Function<E, Iterable<T>>} until 14.0)
   */
  public <T extends @Nullable Object> FluentIterable<T> transformAndConcat(
      Function<? super E, ? extends Iterable<? extends T>> function) {
    return FluentIterable.concat(transform(function));
  }

   *
   * <p><b>{@code Stream} equivalent:</b> {@link Stream#flatMap} (using a function that produces
   * streams, not iterables).
   *
   * @since 13.0 (required {@code Function<E, Iterable<T>>} until 14.0)
   */
  public <T extends @Nullable Object> FluentIterable<T> transformAndConcat(
      Function<? super E, ? extends Iterable<? extends T>> function) {
    return FluentIterable.concat(transform(function));
  }

  }

  /**
   * @since 13.0
   */
  @Override
  public final void addListener(Listener listener, Executor executor) {
    delegate.addListener(listener, executor);
  }

  /**
   * @since 14.0
   */
  @Override
  public final Throwable failureCause() {
    return delegate.failureCause();
  }

  /**
   * @since 15.0
   */
  @CanIgnoreReturnValue
  @Override

 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class Resources {
  private Resources() {}

  /**
   * Returns a {@link ByteSource} that reads from the given URL.
   *
   * @since 14.0
   */
  public static ByteSource asByteSource(URL url) {
    return new UrlByteSource(url);
  }

  /** A byte source that reads from a URL using {@link URL#openStream()}. */

  }

  /**
   * @since 13.0
   */
  @Override
  public final void addListener(Listener listener, Executor executor) {
    delegate.addListener(listener, executor);
  }

  /**
   * @since 14.0
   */
  @Override
  public final Throwable failureCause() {
    return delegate.failureCause();
  }

  /**
   * @since 15.0
   */
  @CanIgnoreReturnValue
  @Override

    return new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file), charset));
  }

  /**
   * Returns a new {@link ByteSource} for reading bytes from the given file.
   *
   * @since 14.0
   */
  public static ByteSource asByteSource(File file) {
    return new FileByteSource(file);
  }

  private static final class FileByteSource extends
      ByteSource
  {

 * new ForwardingWrapperTester().testForwarding(Foo.class, new Function<Foo, Foo>() {
 *   public Foo apply(Foo foo) {
 *     return new ForwardingFoo(foo);
 *   }
 * });
 * }
 *
 * @author Ben Yu
 * @since 14.0
 */
@GwtIncompatible
@J2ktIncompatible
@NullMarked
public final class ForwardingWrapperTester {

  private boolean testsEquals = false;

  /**