BigInteger result = randomPositiveBigInteger(numBits);
    return RANDOM_SOURCE.nextBoolean() ? result : result.negate();
  }

  /**
   * Chooses a number in (-2^numBits, 2^numBits) at random, with density concentrated in numbers of
   * lower magnitude.
   */
  static BigInteger randomBigInteger(int numBits) {
    while (true) {
      if (RANDOM_SOURCE.nextBoolean()) {

    BigInteger result = randomPositiveBigInteger(numBits);
    return RANDOM_SOURCE.nextBoolean() ? result : result.negate();
  }

  /**
   * Chooses a number in (-2^numBits, 2^numBits) at random, with density concentrated in numbers of
   * lower magnitude.
   */
  static BigInteger randomBigInteger(int numBits) {
    while (true) {
      if (RANDOM_SOURCE.nextBoolean()) {

        switch (form.crudMode) {
        case CrudMode.CREATE:
            return OptionalEntity.of(new DataConfig()).map(entity -> {
                entity.setCreatedBy(username);
                entity.setCreatedTime(currentTime);
                return entity;
            });
        case CrudMode.EDIT:
            if (form instanceof EditForm) {

                    appendJson("user", entity.getUser(), buf).append(',');
                    appendJson("search-word", entity.getSearchWord(), buf).append(',');
                    appendJson("hit-count", entity.getHitCount(), buf).append(',');
                    appendJson("query-page-size", entity.getQueryPageSize(), buf).append(',');

        assertFalse(isNotNull.apply(null));
    }

    public void test_apply_boolean() {
        BooleanFunction<Boolean> identity = b -> b != null && b;

        assertTrue(identity.apply(true));
        assertFalse(identity.apply(false));
        assertFalse(identity.apply(null));
    }

    public void test_lambda_expression() {

        return getEntity(form, username, currentTime).map(entity -> {
            entity.setUpdatedBy(username);
            entity.setUpdatedTime(currentTime);
            copyBeanToBean(form, entity, op -> op.exclude(Constants.COMMON_CONVERSION_RULE));
            return entity;
        });
    }

        return getEntity(form, username, currentTime).map(entity -> {
            entity.setUpdatedBy(username);
            entity.setUpdatedTime(currentTime);
            copyBeanToBean(form, entity, op -> op.exclude(Constants.COMMON_CONVERSION_RULE));
            return entity;
        });
    }

    /**
     * Creates an EditBody from a KuromojiItem entity for API responses.
     *
     * @param entity the KuromojiItem entity to convert
     * @param dictId the dictionary ID
     * @return the converted EditBody object
     */
    protected EditBody createEditBody(final KuromojiItem entity, final String dictId) {
        final EditBody body = new EditBody();
        body.id = entity.getId();
        body.dictId = dictId;

    /**
     * Creates an EditBody from a RelatedQuery entity for API responses.
     *
     * @param entity the RelatedQuery entity to convert
     * @return EditBody containing the entity data formatted for editing
     */
    protected EditBody createEditBody(final RelatedQuery entity) {
        final EditBody body = new EditBody();
        copyBeanToBean(entity, body, copyOp -> {
            copyOp.excludeNull();

    }

    /**
     * Creates an EditBody from a User entity.
     *
     * @param entity the user entity to convert
     * @return the converted EditBody
     */
    protected EditBody createEditBody(final User entity) {
        final EditBody body = new EditBody();
        copyBeanToBean(entity, body, copyOp -> {
            copyOp.excludeNull();
        });
        body.password = null;