assertTrue(infinityOpt.isPresent());
        assertTrue(Double.isInfinite(infinityOpt.get()));

        OptionalEntity<Float> negInfinityOpt = OptionalUtil.ofNullable(Float.NEGATIVE_INFINITY);
        assertTrue(negInfinityOpt.isPresent());
        assertTrue(Float.isInfinite(negInfinityOpt.get()));

        // Test with very large strings

  public void testIsPowerOfTwo() {
    for (double x : ALL_DOUBLE_CANDIDATES) {
      boolean expected =
          x > 0
              && !Double.isInfinite(x)
              && !Double.isNaN(x)
              && StrictMath.pow(2.0, DoubleMath.log2(x, FLOOR)) == x;
      assertEquals(expected, DoubleMath.isPowerOfTwo(x));
    }
  }

   * necessarily implemented as, {@code !(Float.isInfinite(value) || Float.isNaN(value))}.
   *
   * <p>Prefer {@link Float#isFinite(float)} instead.
   *
   * @since 10.0
   */
  @InlineMe(replacement = "Float.isFinite(value)")
  public static boolean isFinite(float value) {
    return Float.isFinite(value);
  }

  /**

   * necessarily implemented as, {@code !(Double.isInfinite(value) || Double.isNaN(value))}.
   *
   * <p>Prefer {@link Double#isFinite(double)} instead.
   *
   * @since 10.0
   */
  @InlineMe(replacement = "Double.isFinite(value)")
  public static boolean isFinite(double value) {
    return Double.isFinite(value);
  }

  /**

    //               = x_n y_n - X_n y_n - x_n Y_{n-1} + X_n Y_{n-1}
    //               = (x_n - X_n) (y_n - Y_{n-1})
    xStats.add(x);
    if (isFinite(x) && isFinite(y)) {
      if (xStats.count() > 1) {
        sumOfProductsOfDeltas += (x - xStats.mean()) * (y - yStats.mean());
      }
    } else {
      sumOfProductsOfDeltas = NaN;
    }
    yStats.add(y);
  }

  public void add(double value) {
    if (count == 0) {
      count = 1;
      mean = value;
      min = value;
      max = value;
      if (!isFinite(value)) {
        sumOfSquaresOfDeltas = NaN;
      }
    } else {
      count++;
      if (isFinite(value) && isFinite(mean)) {
        // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15) and (16)
        double delta = value - mean;
        mean += delta / count;

    long count = 1;
    double mean = values.next().doubleValue();
    while (values.hasNext()) {
      double value = values.next().doubleValue();
      count++;
      if (isFinite(value) && isFinite(mean)) {
        // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15)
        mean += (value - mean) / count;
      } else {
        mean = calculateNewMeanNonFinite(mean, value);
      }
    }

    PAST(Timeout.MIN, Timeout.MINUS_SMALL, Timeout.ZERO),
    FUTURE(Timeout.SMALL, Timeout.MAX),
    SMALL(Timeout.SMALL),
    FINITE(Timeout.MIN, Timeout.MINUS_SMALL, Timeout.ZERO, Timeout.SMALL),
    INFINITE(Timeout.LARGE, Timeout.MAX);

    final ImmutableList<Timeout> timeouts;

    TimeoutsToUse(Timeout... timeouts) {
      this.timeouts = ImmutableList.copyOf(timeouts);
    }
  }

    }

    @Override
    public Optional<Long> sizeIfKnown() {
      if (!(sources instanceof Collection)) {
        // Infinite Iterables can cause problems here. Of course, it's true that most of the other
        // methods on this class also have potential problems with infinite  Iterables. But unlike
        // those, this method can cause issues even if the user is dealing with a (finite) slice()

    }
  }

  @SuppressWarnings("InlineMeInliner") // We need to test our method.
  public void testIsFinite() {
    for (double value : NUMBERS) {
      assertThat(Doubles.isFinite(value)).isEqualTo(Double.isFinite(value));
    }
  }

  // We need to test that our method behaves like the JDK method.
  @SuppressWarnings("InlineMeInliner")
  public void testCompare() {
    for (double x : VALUES) {