delegate().putLast(e);
  }

  @Override
  public boolean offerFirst(E e, long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().offerFirst(e, timeout, unit);
  }

  @Override
  public boolean offerLast(E e, long timeout, TimeUnit unit) throws InterruptedException {
    return delegate().offerLast(e, timeout, unit);
  }

  @Override
  public E takeFirst() throws InterruptedException {

   * @param unit the time unit of the warmupPeriod argument
   * @throws IllegalArgumentException if {@code permitsPerSecond} is negative or zero or {@code
   *     warmupPeriod} is negative
   */
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  public static RateLimiter create(double permitsPerSecond, long warmupPeriod, TimeUnit unit) {

  }

  /**
   * Converts an expiration duration/unit pair into a single Long for hashing and equality. Uses
   * nanos to match CacheBuilder implementation.
   */
  @CheckForNull
  private static Long durationInNanos(long duration, @CheckForNull TimeUnit unit) {
    return (unit == null) ? null : unit.toNanos(duration);
  }

  /** Base class for parsing integers. */

    }

    @Override
    public boolean awaitTermination(long timeout, TimeUnit unit) {
      return true;
    }

    @Override
    public void execute(Runnable runnable) {}

    @Override
    public <V> ListenableScheduledFuture<V> schedule(
        Callable<V> callable, long delay, TimeUnit unit) {
      return NeverScheduledFuture.create();
    }

    @Override

  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_T_present() {
    assertEquals("a", Optional.of("a").or("default"));
  }

  public void testOr_T_absent() {
    assertEquals("default", Optional.absent().or("default"));
  }

  @SuppressWarnings("OptionalOfRedundantMethod") // Unit tests for Optional
  public void testOr_supplier_present() {

    }
  }

  /**
   * Returns unit.toNanos(time), additionally ensuring the returned value is not at risk of
   * overflowing or underflowing, by bounding the value between 0 and (Long.MAX_VALUE / 4) * 3.
   * Actually waiting for more than 219 years is not supported!
   */
  private static long toSafeNanos(long time, TimeUnit unit) {
    long timeoutNanos = unit.toNanos(time);

   *     by subsequent {@code get()} calls
   * @param unit the unit that {@code duration} is expressed in
   * @throws IllegalArgumentException if {@code duration} is not positive
   * @since 2.0
   */
  @SuppressWarnings("GoodTime") // Prefer the Duration overload
  public static <T extends @Nullable Object> Supplier<T> memoizeWithExpiration(
      Supplier<T> delegate, long duration, TimeUnit unit) {
    checkNotNull(delegate);

    private final TimeUnit unit;

    private DurationSpec(long duration, TimeUnit unit) {
      this.duration = duration;
      this.unit = unit;
    }

    public static DurationSpec of(long duration, TimeUnit unit) {
      return new DurationSpec(duration, unit);
    }

    @Override
    public int hashCode() {
      return Objects.hashCode(duration, unit);
    }

    @Override

  @Override
  @ParametricNullness
  public V get() {
    return value;
  }

  @Override
  @ParametricNullness
  public V get(long timeout, TimeUnit unit) throws ExecutionException {
    checkNotNull(unit);
    return get();
  }

  @Override
  public boolean isCancelled() {
    return false;
  }

  @Override
  public boolean isDone() {
    return true;
  }

   * @param unit the time unit of the time parameter
   * @param scheduledExecutor The executor service to enforce the timeout.
   */
  @J2ktIncompatible
  @GwtIncompatible // ScheduledExecutorService
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  public final FluentFuture<V> withTimeout(
      long timeout, TimeUnit unit, ScheduledExecutorService scheduledExecutor) {