// Relies on the correctness of sqrt(BigInteger, FLOOR).
  @GwtIncompatible // TODO
  public void testSqrtExact() {
    for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
      BigInteger floor = BigIntegerMath.sqrt(x, FLOOR);
      // We only expect an exception if x was not a perfect square.
      boolean isPerfectSquare = floor.pow(2).equals(x);
      try {
        assertEquals(floor, BigIntegerMath.sqrt(x, UNNECESSARY));

        .roundUnnecessaryShouldThrow()
        .test();
  }

  public void testRoundToDouble_negativeTwoToThe54MinusThree() {
    new RoundToDoubleTester(BigDecimal.valueOf((-1L << 54) - 3))
        .setExpectation(-Math.pow(2, 54), DOWN, CEILING)
        .setExpectation(
            DoubleUtils.nextDown(-Math.pow(2, 54)), FLOOR, UP, HALF_DOWN, HALF_UP, HALF_EVEN)

     * can narrow the possible floor(log10(x)) values to two. For example, if floor(log2(x)) is 6,
     * then 64 <= x < 128, so floor(log10(x)) is either 1 or 2.
     */
    int y = maxLog10ForLeadingZeros[Long.numberOfLeadingZeros(x)];
    /*
     * y is the higher of the two possible values of floor(log10(x)). If x < 10^y, then we want the

import static com.google.common.truth.Truth.assertThat;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.DOWN;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.HALF_DOWN;
import static java.math.RoundingMode.HALF_EVEN;
import static java.math.RoundingMode.HALF_UP;
import static java.math.RoundingMode.UNNECESSARY;

    // is an integer 199*index/2. If index is odd, that is halfway between floor(199*index/2) and
    // ceil(199*index/2).
    if (index % 2 == 0) {
      int position = IntMath.divide(199 * index, 2, UNNECESSARY);
      return PSEUDORANDOM_DATASET_SORTED.get(position);
    } else {
      int positionFloor = IntMath.divide(199 * index, 2, FLOOR);
      int positionCeil = IntMath.divide(199 * index, 2, CEILING);

    // is an integer 199*index/2. If index is odd, that is halfway between floor(199*index/2) and
    // ceil(199*index/2).
    if (index % 2 == 0) {
      int position = IntMath.divide(199 * index, 2, UNNECESSARY);
      return PSEUDORANDOM_DATASET_SORTED.get(position);
    } else {
      int positionFloor = IntMath.divide(199 * index, 2, FLOOR);
      int positionCeil = IntMath.divide(199 * index, 2, CEILING);

    private @Nullable AvlNode<E> floor(Comparator<? super E> comparator, @ParametricNullness E e) {
      int cmp = comparator.compare(e, getElement());
      if (cmp > 0) {
        return (right == null) ? this : MoreObjects.firstNonNull(right.floor(comparator, e), this);
      } else if (cmp == 0) {
        return this;
      } else {
        return (left == null) ? null : left.floor(comparator, e);
      }
    }

import static com.google.common.truth.Truth.assertThat;
import static java.math.RoundingMode.CEILING;
import static java.math.RoundingMode.DOWN;
import static java.math.RoundingMode.FLOOR;
import static java.math.RoundingMode.HALF_DOWN;
import static java.math.RoundingMode.HALF_EVEN;
import static java.math.RoundingMode.HALF_UP;
import static java.math.RoundingMode.UNNECESSARY;

    private @Nullable AvlNode<E> floor(Comparator<? super E> comparator, @ParametricNullness E e) {
      int cmp = comparator.compare(e, getElement());
      if (cmp > 0) {
        return (right == null) ? this : MoreObjects.firstNonNull(right.floor(comparator, e), this);
      } else if (cmp == 0) {
        return this;
      } else {
        return (left == null) ? null : left.floor(comparator, e);
      }
    }

    }

    @Override
    public @Nullable V lower(@ParametricNullness V v) {
      return getSortedSetDelegate().lower(v);
    }

    @Override
    public @Nullable V floor(@ParametricNullness V v) {
      return getSortedSetDelegate().floor(v);
    }

    @Override
    public @Nullable V ceiling(@ParametricNullness V v) {
      return getSortedSetDelegate().ceiling(v);
    }

    @Override