* contains both {@link Double#POSITIVE_INFINITY} and {@link Double#NEGATIVE_INFINITY} then the
   * result is {@link Double#NaN}. If it contains {@link Double#POSITIVE_INFINITY} and finite values
   * only or {@link Double#POSITIVE_INFINITY} only, the result is {@link Double#POSITIVE_INFINITY}.
   * If it contains {@link Double#NEGATIVE_INFINITY} and finite values only or {@link

   * contains both {@link Double#POSITIVE_INFINITY} and {@link Double#NEGATIVE_INFINITY} then the
   * result is {@link Double#NaN}. If it contains {@link Double#POSITIVE_INFINITY} and finite values
   * only or {@link Double#POSITIVE_INFINITY} only, the result is {@link Double#POSITIVE_INFINITY}.
   * If it contains {@link Double#NEGATIVE_INFINITY} and finite values only or {@link

      if (upper == POSITIVE_INFINITY) {
        // Return NaN when lower == NEGATIVE_INFINITY and upper == POSITIVE_INFINITY:
        return NaN;
      }
      // Return NEGATIVE_INFINITY when NEGATIVE_INFINITY == lower <= upper < POSITIVE_INFINITY:
      return NEGATIVE_INFINITY;
    }
    if (upper == POSITIVE_INFINITY) {

  public void testRoundInfiniteToIntAlwaysFails() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {
      assertThrows(
          ArithmeticException.class, () -> DoubleMath.roundToInt(Double.POSITIVE_INFINITY, mode));
      assertThrows(
          ArithmeticException.class, () -> DoubleMath.roundToInt(Double.NEGATIVE_INFINITY, mode));
    }
  }

  @GwtIncompatible // DoubleMath.roundToLong(double, RoundingMode)

   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link
   * Double#NEGATIVE_INFINITY}, or {@link Double#NaN}) then the result is {@link Double#NaN}.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double populationCovariance() {

    assertEvents("R0.00", "R1.00", "R1.00");

    limiter.setRate(Double.POSITIVE_INFINITY);
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    assertEvents("R1.00", "R0.00", "R0.00");
  }

  public void testInfinity_warmUpTimeElapsed() {
    RateLimiter limiter = RateLimiter.create(Double.POSITIVE_INFINITY, 10, SECONDS, 3.0, stopwatch);
    stopwatch.instant += 1000000;
    limiter.setRate(1.0);

    assertEvents("R0.00", "R1.00", "R1.00");

    limiter.setRate(Double.POSITIVE_INFINITY);
    limiter.acquire();
    limiter.acquire();
    limiter.acquire();
    assertEvents("R1.00", "R0.00", "R0.00");
  }

  public void testInfinity_warmUpTimeElapsed() {
    RateLimiter limiter = RateLimiter.create(Double.POSITIVE_INFINITY, 10, SECONDS, 3.0, stopwatch);
    stopwatch.instant += 1000000;
    limiter.setRate(1.0);

   * times, due to numerical errors.
   *
   * <h3>Non-finite values</h3>
   *
   * <p>If the dataset contains any non-finite values ({@link Double#POSITIVE_INFINITY}, {@link
   * Double#NEGATIVE_INFINITY}, or {@link Double#NaN}) then the result is {@link Double#NaN}.
   *
   * @throws IllegalStateException if the dataset is empty
   */
  public double populationCovariance() {

    ImmutableDoubleArray iia =
        ImmutableDoubleArray.of(-0.0, 0.0, Double.MAX_VALUE, Double.POSITIVE_INFINITY, Double.NaN);
    assertThat(iia.indexOf(-0.0)).isEqualTo(0);
    assertThat(iia.indexOf(0.0)).isEqualTo(1);
    assertThat(iia.indexOf(Double.MAX_VALUE)).isEqualTo(2);
    assertThat(iia.indexOf(Double.POSITIVE_INFINITY)).isEqualTo(3);
    assertThat(iia.indexOf(Double.NaN)).isEqualTo(4);
  }

   * representable as a double, but {@code roundToDouble(BigDecimal.valueOf(2).pow(2000), HALF_UP)}
   * will return {@code Double.MAX_VALUE}, not {@code Double.POSITIVE_INFINITY}.
   *
   * <p>For the case of {@link RoundingMode#HALF_EVEN}, this implementation uses the IEEE 754
   * default rounding mode: if the two nearest representable values are equally near, the one with