}

  @CollectionSize.Require(SEVERAL)
  public void testFloorHole() {
    resetWithHole();
    assertEquals(a, navigableSet.floor(a));
    assertEquals(a, navigableSet.floor(b));
    assertEquals(c, navigableSet.floor(c));
  }

  @CollectionSize.Require(SEVERAL)
  public void testCeilingHole() {
    resetWithHole();
    assertEquals(a, navigableSet.ceiling(a));

    return new SafeTreeSet<>(delegate.descendingSet());
  }

  @Override
  public E first() {
    return delegate.first();
  }

  @Override
  public @Nullable E floor(E e) {
    return delegate.floor(checkValid(e));
  }

  @Override
  public SortedSet<E> headSet(E toElement) {
    return headSet(toElement, false);
  }

  @Override

    do {
      result = randomNonNegativeBigInteger(numBits);
    } while (result.signum() == 0);
    return result;
  }

  /**
   * Generates a number in [0, 2^numBits) with an exponential distribution. The floor of the log2 of
   * the result is chosen uniformly at random in [0, numBits), and then the result is chosen in that
   * range uniformly at random. Zero is treated as having log2 == 0.
   */

            }
            roundFloor = toX(roundFloorAsDouble, RoundingMode.FLOOR);
          }

          X deltaToFloor = minus(x, roundFloor);
          X deltaToCeiling = minus(roundCeiling, x);
          int diff = deltaToFloor.compareTo(deltaToCeiling);
          if (diff < 0) { // closer to floor
            return roundFloorAsDouble;
          } else if (diff > 0) { // closer to ceiling

  }

  @Override
  @CheckForNull
  public E floor(@ParametricNullness E e) {
    return delegate().floor(e);
  }

  /**
   * A sensible definition of {@link #floor} in terms of the {@code descendingIterator} method of
   * {@link #headSet(Object, boolean)}. If you override {@link #headSet(Object, boolean)}, you may
   * wish to override {@link #floor} to forward to this implementation.
   */
  @CheckForNull

  @CheckForNull
  public E lower(E element) {
    return forward.higher(element);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    return forward.ceiling(element);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {
    return forward.floor(element);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    return forward.lower(element);
  }

  }

  @Override
  @CheckForNull
  public E floor(@ParametricNullness E e) {
    return delegate().floor(e);
  }

  /**
   * A sensible definition of {@link #floor} in terms of the {@code descendingIterator} method of
   * {@link #headSet(Object, boolean)}. If you override {@link #headSet(Object, boolean)}, you may
   * wish to override {@link #floor} to forward to this implementation.
   */
  @CheckForNull

  }

  @CollectionSize.Require(SEVERAL)
  public void testFloorHole() {
    resetWithHole();
    assertEquals(a, navigableSet.floor(a));
    assertEquals(a, navigableSet.floor(b));
    assertEquals(c, navigableSet.floor(c));
  }

  @CollectionSize.Require(SEVERAL)
  public void testCeilingHole() {
    resetWithHole();
    assertEquals(a, navigableSet.ceiling(a));

      return standardSubSet(fromElement, toElement);
    }

    @Override
    public @Nullable T lower(T e) {
      return standardLower(e);
    }

    @Override
    public @Nullable T floor(T e) {
      return standardFloor(e);
    }

    @Override
    public @Nullable T ceiling(T e) {
      return standardCeiling(e);
    }

    @Override
    public @Nullable T higher(T e) {

  private static final BigInteger[] nonzero2 = new BigInteger[ARRAY_SIZE];
  private static final BigInteger[] positive = new BigInteger[ARRAY_SIZE];

  @Param({"DOWN", "UP", "FLOOR", "CEILING", "HALF_EVEN", "HALF_UP", "HALF_DOWN"})
  RoundingMode mode;

  @BeforeExperiment
  void setUp() {
    for (int i = 0; i < ARRAY_SIZE; i++) {
      positive[i] = randomPositiveBigInteger(1024);