* @param period the period between successive executions of the task
     * @since 28.0 (but only since 33.4.0 in the Android flavor)
     */
    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

     * @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