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

  /**
   * Invokes {@code lock.}{@link Lock#tryLock(long, TimeUnit) tryLock(timeout, unit)}
   * uninterruptibly.