@VisibleForTesting
  static final class ValueEntry<K extends @Nullable Object, V extends @Nullable Object>
      extends SimpleImmutableEntry<K, V> {
    final int smearedValueHash;

    @Nullable ValueEntry<K, V> nextInValueBucket;

    private @Nullable ValueEntry<K, V> predecessorInValueSet;
    private @Nullable ValueEntry<K, V> successorInValueSet;

    private @Nullable ValueEntry<K, V> predecessorInMultimap;

  @VisibleForTesting
  static final class ValueEntry<K extends @Nullable Object, V extends @Nullable Object>
      extends SimpleImmutableEntry<K, V> {
    final int smearedValueHash;

    @Nullable ValueEntry<K, V> nextInValueBucket;

    private @Nullable ValueEntry<K, V> predecessorInValueSet;
    private @Nullable ValueEntry<K, V> successorInValueSet;

    private @Nullable ValueEntry<K, V> predecessorInMultimap;

        return oldValue;
      }
    }

    int valueHash = smearedHash(value);
    int valueEntry = findEntryByValue(value, valueHash);
    if (force) {
      if (valueEntry != ABSENT) {
        removeEntryValueHashKnown(valueEntry, valueHash);
      }
    } else {
      checkArgument(valueEntry == ABSENT, "Value already present: %s", value);
    }

    ensureCapacity(size + 1);
    keys[size] = key;