@Override
    public int count(@Nullable Object element) {
      Collection<V> values = map.get(element);
      return (values == null) ? 0 : values.size();
    }

    @Override
    public ImmutableSet<K> elementSet() {
      return keySet();
    }

    @Override
    public int size() {
      return ImmutableMultimap.this.size();
    }

    @Override
    Multiset.Entry<K> getEntry(int index) {

    @Override
    public int count(@Nullable Object element) {
      Collection<V> values = map.get(element);
      return (values == null) ? 0 : values.size();
    }

    @Override
    public ImmutableSet<K> elementSet() {
      return keySet();
    }

    @Override
    public int size() {
      return ImmutableMultimap.this.size();
    }

    @Override
    Multiset.Entry<K> getEntry(int index) {

   */
  @GwtIncompatible
  @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(elementSet().comparator());
    Serialization.writeMultiset(this, stream);
  }

  @J2ktIncompatible
  @GwtIncompatible
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {

   */
  @GwtIncompatible
  @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {
    stream.defaultWriteObject();
    stream.writeObject(elementSet().comparator());
    Serialization.writeMultiset(this, stream);
  }

  @J2ktIncompatible
  @GwtIncompatible
    private void readObject(ObjectInputStream stream) throws IOException, ClassNotFoundException {