* @since 33.4.0 (but since 28.0 in the JRE flavor)
     */
    @IgnoreJRERequirement // Users will use this only if they're already using Duration
    public static Scheduler newFixedRateSchedule(Duration initialDelay, Duration period) {
      return newFixedRateSchedule(
          toNanosSaturated(initialDelay), toNanosSaturated(period), NANOSECONDS);
    }

    /**
     * Returns a {@link Scheduler} that schedules the task using the {@link

    assertEquals(DELAY, delay);
    assertEquals(UNIT, unit);
    assertEquals(testRunnable, command);
  }

  public void testFixedRateSchedule() {
    Scheduler schedule = Scheduler.newFixedRateSchedule(INITIAL_DELAY, DELAY, UNIT);
    Cancellable unused =
        schedule.schedule(
            null,
            new ScheduledThreadPoolExecutor(1) {
              @Override

    assertEquals(DELAY, delay);
    assertEquals(UNIT, unit);
    assertEquals(testRunnable, command);
  }

  public void testFixedRateSchedule() {
    Scheduler schedule = Scheduler.newFixedRateSchedule(INITIAL_DELAY, DELAY, UNIT);
    Cancellable unused =
        schedule.schedule(
            null,
            new ScheduledThreadPoolExecutor(1) {
              @Override