@GwtIncompatible // serialization
    Object writeReplace() {
      return new InverseSerializedForm<>(RegularImmutableBiMap.this);
    }

    @J2ktIncompatible // java.io.ObjectInputStream
    private void readObject(ObjectInputStream stream) throws InvalidObjectException {
      throw new InvalidObjectException("Use InverseSerializedForm");
    }
  }

  @J2ktIncompatible // serialization