*/

    @Override
    @ParametricNullness
    K checkKey(@ParametricNullness K key) {
      return super.inverse.checkValue(key);
    }

    @Override
    @ParametricNullness
    V checkValue(@ParametricNullness V value) {
      return super.inverse.checkKey(value);
    }

    /**
     * @serialData the forward bimap
     */
    @GwtIncompatible

  @GwtIncompatible
  public Class<V> valueType() {
    return valueTypeOrObjectUnderJ2cl;
  }

  @Override
  K checkKey(K key) {
    return checkNotNull(key);
  }

  @Override
  V checkValue(V value) {
    return checkNotNull(value);
  }

  /**
   * @serialData the key class, value class, number of entries, first key, first value, second key,
   *     second value, and so on.
   */