*     permits become available per second
   * @throws IllegalArgumentException if {@code permitsPerSecond} is negative or zero
   */
  // TODO(user): "This is equivalent to
  // {@code createWithCapacity(permitsPerSecond, 1, TimeUnit.SECONDS)}".
  public static RateLimiter create(double permitsPerSecond) {
    /*
     * The default RateLimiter configuration can save the unused permits of up to one second. This