*/
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  @IgnoreJRERequirement // Users will use this only if they're already using Duration.
  public static boolean tryAcquireUninterruptibly(Semaphore semaphore, Duration timeout) {
    return tryAcquireUninterruptibly(semaphore, toNanosSaturated(timeout), TimeUnit.NANOSECONDS);
  }

  /**
   * Invokes {@code semaphore.}{@link Semaphore#tryAcquire(int, long, TimeUnit) tryAcquire(1,