{
              int delta = random.nextInt(6); // [0, 5]
              int oldValue = multiset.remove(key, delta);
              deltas[keyIndex] -= min(delta, oldValue);
              break;
            }
          case REMOVE_EXACTLY:
            {
              int delta = random.nextInt(5); // [0, 4]
              if (multiset.removeExactly(key, delta)) {
                deltas[keyIndex] -= delta;

        while (!diff) {
          int delta = (1 << i) | (1 << j);
          int key1 = rand.nextInt();
          // apply delta
          int key2 = key1 ^ delta;

          // get hashes
          int hash1 = function.hashInt(key1).asInt();
          int hash2 = function.hashInt(key2).asInt();

          // this 2-bit candidate delta is not a characteristic
          // if deltas are different

  public long decrementAndGet(K key) {
    return addAndGet(key, -1);
  }

  /**
   * Adds {@code delta} to the value currently associated with {@code key}, and returns the new
   * value.
   */
  @CanIgnoreReturnValue
  public long addAndGet(K key, long delta) {
    return accumulateAndGet(key, delta, Long::sum);
  }

  /**

        while (!diff) {
          int delta = (1 << i) | (1 << j);
          int key1 = rand.nextInt();
          // apply delta
          int key2 = key1 ^ delta;

          // get hashes
          int hash1 = function.hashInt(key1).asInt();
          int hash2 = function.hashInt(key2).asInt();

          // this 2-bit candidate delta is not a characteristic
          // if deltas are different

   * size() as a hint only.
   *
   * @param delta the difference between the true size of the collection and the values returned by
   *     the size method
   */
  public static <T extends @Nullable Object> Collection<T> misleadingSizeCollection(int delta) {
    // It would be nice to be able to return a real concurrent

   * size() as a hint only.
   *
   * @param delta the difference between the true size of the collection and the values returned by
   *     the size method
   */
  public static <T extends @Nullable Object> Collection<T> misleadingSizeCollection(int delta) {
    // It would be nice to be able to return a real concurrent

      // http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax

      long delta = a - b; // can't overflow, since a and b are nonnegative

      long minDeltaOrZero = delta & (delta >> (Long.SIZE - 1));
      // equivalent to Math.min(delta, 0)

      a = delta - minDeltaOrZero - minDeltaOrZero; // sets a to Math.abs(a - b)
      // a is now nonnegative and even

  }

  public void testToArray_threadSafe() {
    for (int delta : new int[] {+1, 0, -1}) {
      for (int i = 0; i < VALUES.length; i++) {
        List<Character> list = Chars.asList(VALUES).subList(0, i);
        Collection<Character> misleadingSize = Helpers.misleadingSizeCollection(delta);
        misleadingSize.addAll(list);
        char[] arr = Chars.toArray(misleadingSize);

  }

  public void testToArray_threadSafe() {
    for (int delta : new int[] {+1, 0, -1}) {
      for (int i = 0; i < VALUES.length; i++) {
        List<Double> list = Doubles.asList(VALUES).subList(0, i);
        Collection<Double> misleadingSize = Helpers.misleadingSizeCollection(delta);
        misleadingSize.addAll(list);
        double[] arr = Doubles.toArray(misleadingSize);

  }

  public void testToArray_threadSafe() {
    for (int delta : new int[] {+1, 0, -1}) {
      for (int i = 0; i < VALUES.length; i++) {
        List<Integer> list = Ints.asList(VALUES).subList(0, i);
        Collection<Integer> misleadingSize = Helpers.misleadingSizeCollection(delta);
        misleadingSize.addAll(list);
        int[] arr = Ints.toArray(misleadingSize);