*
   * @param currentValue the current value (of either base or a cell)
   * @param newValue the argument from a user update call
   * @return result of the update function
   */
  abstract long fn(long currentValue, long newValue);

  /**
   * Handles cases of updates involving initialization, resizing, creating new Cells, and/or

   *
   * @param currentValue the current value (of either base or a cell)
   * @param newValue the argument from a user update call
   * @return result of the update function
   */
  abstract long fn(long currentValue, long newValue);

  /**
   * Handles cases of updates involving initialization, resizing, creating new Cells, and/or

    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);
  }

  class MapEntry extends AbstractEntry<K> {

   *     flooding attack
   */
  @CanIgnoreReturnValue
  @CheckForNull
  static <K, V> ImmutableMapEntry<K, V> checkNoConflictInKeyBucket(
      Object key,
      Object newValue,
      @CheckForNull ImmutableMapEntry<K, V> keyBucketHead,
      boolean throwIfDuplicateKeys)
      throws BucketOverflowException {
    int bucketSize = 0;

  }

  @CanIgnoreReturnValue
  @Override
  public boolean replace(K key, @CheckForNull 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);
  }

  @CheckForNull
  @CanIgnoreReturnValue
  @Override

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

  }

  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) {

  }

  @CanIgnoreReturnValue
  @Override
  public boolean replace(K key, @CheckForNull 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);
  }

  @CheckForNull
  @CanIgnoreReturnValue
  @Override

      @ParametricNullness K key,
      boolean containedKey,
      @CheckForNull 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
  @CheckForNull

      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());