BigInteger x4 = x.shiftLeft(2);
      // sqrt(x) <= result + 0.5, so 4 * x <= (result + 0.5)^2 * 4
      // (result + 0.5)^2 * 4 = (result^2 + result)*4 + 1
      assertTrue(x4.compareTo(plusHalfSquared) <= 0);
      BigInteger minusHalfSquared = result.pow(2).subtract(result).shiftLeft(2).add(ONE);
      // sqrt(x) > result - 0.5, so 4 * x > (result - 0.5)^2 * 4

      BigInteger x4 = x.shiftLeft(2);
      // sqrt(x) <= result + 0.5, so 4 * x <= (result + 0.5)^2 * 4
      // (result + 0.5)^2 * 4 = (result^2 + result)*4 + 1
      assertTrue(x4.compareTo(plusHalfSquared) <= 0);
      BigInteger minusHalfSquared = result.pow(2).subtract(result).shiftLeft(2).add(ONE);
      // sqrt(x) > result - 0.5, so 4 * x > (result - 0.5)^2 * 4

        return (result[0] == 0) ? this : rebalance();
      } else if (cmp > 0) {
        AvlNode<E> initRight = right;
        if (initRight == null) {
          result[0] = 0;
          return this;
        }

        right = initRight.remove(comparator, e, count, result);

        if (result[0] > 0) {
          if (count >= result[0]) {
            this.distinctElements--;
            this.totalCount -= result[0];

         * results can exceed 2^63.
         */
        long result = times2ToThe32Mod(aHi * bHi /* < 2^62 */, m); // < m < 2^63
        result += aHi * bLo; // aHi * bLo < 2^63, result < 2^64
        if (result < 0) {
          result = UnsignedLongs.remainder(result, m);
        }
        // result < 2^63 again
        result += aLo * bHi; // aLo * bHi < 2^63, result < 2^64

      checkNonnegative(distance, "distance");
      long result = origin + distance;
      if (result < 0) {
        checkArgument(origin < 0, "overflow");
      }
      return result;
    }

    @Override
    public long distance(Long start, Long end) {
      long result = end - start;
      if (end > start && result < 0) { // overflow
        return Long.MAX_VALUE;
      }

    public List<@Nullable V> combine(List<@Nullable Present<V>> values) {
      List<@Nullable V> result = newArrayListWithCapacity(values.size());
      for (Present<V> element : values) {
        result.add(element != null ? element.value : null);
      }
      return unmodifiableList(result);
    }
  }

  /** The result of a successful {@code Future}. */
  private static final class Present<V extends @Nullable Object> {

    for (CollectStrategy scheme : CollectStrategy.values()) {
      A finalAccum = scheme.result(collector, inputs);
      if (collector.characteristics().contains(Collector.Characteristics.IDENTITY_FINISH)) {
        @SuppressWarnings("unchecked") // `R` and `A` match for an `IDENTITY_FINISH`
        R result = (R) finalAccum;
        assertEquivalent(expectedResult, result);
      }

  @Override
  public SortedMultiset<E> descendingMultiset() {
    UnmodifiableSortedMultiset<E> result = descendingMultiset;
    if (result == null) {
      result = new UnmodifiableSortedMultiset<E>(delegate().descendingMultiset());
      result.descendingMultiset = this;
      return descendingMultiset = result;
    }
    return result;
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {

    final String result = MoreObjects.toStringHelper(new TestClass()).add("Hello", null).toString();

    assertEquals("TestClass{Hello=null}", result);
  }

  public void testToStringLenient_addWithNullValue() {
    final String result = MoreObjects.toStringHelper(new TestClass()).add("Hello", null).toString();
    assertTrue(result, result.matches(".*\\{Hello\\=null\\}"));
  }

  public static <K, V> ConcurrentMapTestSuiteBuilder<K, V> using(TestMapGenerator<K, V> generator) {
    ConcurrentMapTestSuiteBuilder<K, V> result = new ConcurrentMapTestSuiteBuilder<>();
    result.usingGenerator(generator);
    return result;
  }

  @SuppressWarnings("rawtypes") // class literals
  static final List<? extends Class<? extends AbstractTester>> TESTERS =
      Arrays.asList(