public ImmutableCollection<V> values() {
    return (ImmutableCollection<V>) super.values();
  }

  @Override
  abstract ImmutableCollection<V> createValues();

  @Override
  final Iterator<V> valuesIterator() {
    throw new AssertionError("should never be called");
  }

  /**
   * {@inheritDoc}
   *
   * @throws NullPointerException if {@code columnKey} is {@code null}
   */
  @Override

    }

    @Override
    public void clear() {
      CompactHashMap.this.clear();
    }

    @Override
    public Iterator<V> iterator() {
      return valuesIterator();
    }
  }

  Iterator<V> valuesIterator() {
    Map<K, V> delegate = delegateOrNull();
    if (delegate != null) {
      return delegate.values().iterator();
    }
    return new Itr<V>() {
      @Override

   *
   * @return collection of values
   */
  @Override
  public Collection<@Nullable V> values() {
    return super.values();
  }

  @Override
  Iterator<@Nullable V> valuesIterator() {
    return new AbstractIndexedListIterator<@Nullable V>(size()) {
      @Override
      protected @Nullable V get(int index) {
        return getValue(index);
      }
    };
  }

  @Override

   *
   * @return collection of values
   */
  @Override
  public Collection<@Nullable V> values() {
    return super.values();
  }

  @Override
  Iterator<@Nullable V> valuesIterator() {
    return new AbstractIndexedListIterator<@Nullable V>(size()) {
      @Override
      protected @Nullable V get(int index) {
        return getValue(index);
      }
    };
  }