return (K) keys[index];
  }

  int getValue(int index) {
    checkElementIndex(index, size);
    return values[index];
  }

  void setValue(int index, int newValue) {
    checkElementIndex(index, size);
    values[index] = newValue;
  }

  Entry<K> getEntry(int index) {
    checkElementIndex(index, size);
    return new MapEntry(index);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfAbsent_nullTreatedAsAbsent() {
    initMapWithNullValue();
    assertEquals(
        "computeIfAbsent(presentAssignedToNull, function) should return newValue",
        getValueForNullKey(),
        getMap()
            .computeIfAbsent(
                getKeyForNullValue(),
                k -> {
                  assertEquals(getKeyForNullValue(), k);

                    V newValue = (oldValue == null) ? e.getValue() : remapping.merge(oldValue, e.getValue());
                    if (newValue == null) {
                        remove(key);
                    } else if (newValue != oldValue) {
                        map.put(key, newValue);
                    }
                }
            } else {

  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfAbsent_nullTreatedAsAbsent() {
    initMapWithNullValue();
    assertEquals(
        "computeIfAbsent(presentAssignedToNull, function) should return newValue",
        getValueForNullKey(),
        getMap()
            .computeIfAbsent(
                getKeyForNullValue(),
                k -> {
                  assertEquals(getKeyForNullValue(), k);

  }

  @CanIgnoreReturnValue
  @Override
  public boolean replace(K key, @Nullable V oldValue, V newValue) {
    checkNotNull(key);
    checkNotNull(newValue);
    if (oldValue == null) {
      return false;
    }
    int hash = hash(key);
    return segmentFor(hash).replace(key, hash, oldValue, newValue);
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V replace(K key, V value) {

      @ParametricNullness K key,
      boolean containedKey,
      @Nullable V oldValue,
      @ParametricNullness V newValue) {
    if (containedKey) {
      // The cast is safe because of the containedKey check.
      removeFromInverseMap(uncheckedCastNullableTToT(oldValue));
    }
    inverse.delegate.put(newValue, key);
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V remove(@Nullable Object key) {

      Entry<Cut<K>, RangeMapEntry<K, V>> entry = backingItr.next();
      V newValue = remappingFunction.apply(entry.getValue().getValue(), value);
      if (newValue == null) {
        backingItr.remove();
      } else {
        entry.setValue(
            new RangeMapEntry<K, V>(
                entry.getValue().getLowerBound(), entry.getValue().getUpperBound(), newValue));
      }
    }

    entriesByLowerBound.putAll(gaps.build());

  }

  private static void insertIntoReplica(Map<Integer, AtomicInteger> replica, int newValue) {
    if (replica.containsKey(newValue)) {
      replica.get(newValue).incrementAndGet();
    } else {
      replica.put(newValue, new AtomicInteger(1));
    }
  }

  private static void removeMinFromReplica(
      SortedMap<Integer, AtomicInteger> replica, int minValue) {

				if isReservedOrInvalidBucket(volInfo.Name, false) {
					continue
				}

				healBuckets.Compute(volInfo.Name, func(oldValue VolInfo, loaded bool) (newValue VolInfo, del bool) {
					if loaded {
						newValue = oldValue
						newValue.count = oldValue.count + 1
						return newValue, false
					}
					return VolInfo{
						Name:    volInfo.Name,
						Created: volInfo.Created,
						count:   1,
					}, false
				})

    private @Nullable T value;

    @Nullable T get() {
      return value;
    }

    void checkAndSet(@Nullable T expected, @Nullable T newValue) {
      if (value != expected) {
        throw new ConcurrentModificationException();
      }
      value = newValue;
    }

    void clear() {
      value = null;
    }
  }

  private static final class AvlNode<E extends @Nullable Object> {