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) {

      for (double first : ImmutableList.of(1.1, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
        values[0] = first;
        values[1] = -44.44;
        for (double third : ImmutableList.of(33.33, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
          values[2] = third;
          values[3] = 555.555;
          for (double fifth : ImmutableList.of(-2.2, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
            values[4] = fifth;

    new RoundToDoubleTester(maxDoubleAsBD)
        .setExpectation(Double.MAX_VALUE, DOWN, FLOOR, HALF_EVEN, HALF_UP, HALF_DOWN)
        .setExpectation(Double.POSITIVE_INFINITY, UP, CEILING)
        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_wayTooBig() {
    BigDecimal bi = BigDecimal.valueOf(2).pow(2 * Double.MAX_EXPONENT);

    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);

    checkTryParse(Float.POSITIVE_INFINITY, "Infinity");
    checkTryParse(Float.POSITIVE_INFINITY, "+Infinity");
    checkTryParse(Float.NEGATIVE_INFINITY, "-Infinity");
  }

  private static final String[] BAD_TRY_PARSE_INPUTS = {
    "",
    "+-",
    "+-0",
    " 5",
    "32 ",
    " 55 ",
    "infinity",
    "POSITIVE_INFINITY",
    "0x9A",
    "0x9A.bE-5",
    ".",

    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);
  }

    new RoundToDoubleTester(maxDoubleAsBD)
        .setExpectation(Double.MAX_VALUE, DOWN, FLOOR, HALF_EVEN, HALF_UP, HALF_DOWN)
        .setExpectation(Double.POSITIVE_INFINITY, UP, CEILING)
        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_wayTooBig() {
    BigDecimal bi = BigDecimal.valueOf(2).pow(2 * Double.MAX_EXPONENT);

      for (double first : ImmutableList.of(1.1, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
        values[0] = first;
        values[1] = -44.44;
        for (double third : ImmutableList.of(33.33, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
          values[2] = third;
          values[3] = 555.555;
          for (double fifth : ImmutableList.of(-2.2, POSITIVE_INFINITY, NEGATIVE_INFINITY, NaN)) {
            values[4] = fifth;

import static com.google.common.truth.Truth.assertWithMessage;
import static java.lang.Double.NEGATIVE_INFINITY;
import static java.lang.Double.NaN;
import static java.lang.Double.POSITIVE_INFINITY;
import static java.lang.Math.sqrt;
import static org.junit.Assert.assertThrows;

import com.google.common.collect.ImmutableList;
import com.google.common.math.StatsTesting.ManyValues;

    assertThrows(IllegalStateException.class, () -> EMPTY_PAIRED_STATS.populationCovariance());
    assertThat(ONE_VALUE_PAIRED_STATS.populationCovariance()).isWithin(0.0).of(0.0);
    assertThat(createSingleStats(Double.POSITIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NEGATIVE_INFINITY, 1.23).populationCovariance()).isNaN();
    assertThat(createSingleStats(Double.NaN, 1.23).populationCovariance()).isNaN();