// Test constructor with cause only
        Throwable cause = new IllegalArgumentException("Cause exception");
        FessSystemException exception = new FessSystemException(cause);

        assertEquals(cause, exception.getCause());
        // When constructed with cause only, message contains the cause's toString()
        assertTrue(exception.getMessage().contains(cause.getClass().getName()));

This can save everyone a lot of time and frustration.

For any non-trivial change, we need to be able to answer these questions:

* Why is this change done? What's the use case?
* For user-facing features, what will the API look like?
* What test cases should it have? What could go wrong?

    }

    @Test
    public void test_constructorWithMessageAndCause() {
        // Test constructor with message and cause
        String message = "GSA configuration error with cause";
        Throwable cause = new RuntimeException("Root cause exception");
        GsaConfigException exception = new GsaConfigException(message, cause);

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());

    @Test
    public void test_constructor_withServletExceptionWithCause() {
        // Create a root cause exception
        String rootCauseMessage = "Root cause error";
        Exception rootCause = new Exception(rootCauseMessage);

        // Create a ServletException with the root cause
        String servletErrorMessage = "Servlet error with cause";
        ServletException servletException = new ServletException(servletErrorMessage, rootCause);

        assertEquals("admin", ldapManager.normalizePermissionName("admin"));
    }

    // ========================================================================
    // Tests for Edge Cases
    // ========================================================================

    @Test
    public void test_escapeLDAPSearchFilter_withUnicodeCharacters() {
        LdapManager ldapManager = new LdapManager();

        for (final BooleanClause clause : booleanQuery.clauses()) {
            final QueryBuilder queryBuilder = getQueryProcessor().execute(context, clause.query(), boost);
            if (queryBuilder != null) {
                switch (clause.occur()) {
                case MUST:
                    boolQuery.must(queryBuilder);
                    break;
                case SHOULD:

    }

    // ========== Security Tests ==========

    /**
     * Security test: Verify that unregistered classes are rejected during serialization.
     * This test ensures that the Kryo registration requirement is working correctly.
     * Unregistered classes should throw an exception to prevent potential RCE attacks.
     */
    @Test
    public void test_security_unregisteredClassRejected() {

     * preventing deserialization of arbitrary classes that could lead to RCE vulnerabilities.
     * Only explicitly registered classes can be serialized/deserialized.
     * </p>
     */
    public DataSerializer() {
        kryoThreadLocal = ThreadLocal.withInitial(() -> {
            final Kryo kryo = new Kryo();
            // Enable registration requirement for security - only registered classes can be deserialized

- **Language only**: `fess_label_en.properties`, `fess_label_ja.properties`
- **Language + Region**: `fess_label_pt_BR.properties`, `fess_label_zh_CN.properties`, `fess_label_zh_TW.properties`
- **Special cases**: Kurdish uses `fess_label_ckb_IQ.properties`

## Step-by-Step Guide

### 1. Create Language Resource Files

Copy the base English files as templates:

```bash
cd src/main/resources

        List<BooleanClause> clauses = ((BooleanQuery) query).clauses();
        assertEquals(TermQuery.class, clauses.get(0).query().getClass());
        assertEquals("_default:fess", clauses.get(0).query().toString());
        assertEquals(Occur.MUST, clauses.get(0).occur());
        assertEquals(TermQuery.class, clauses.get(1).query().getClass());
        assertEquals("_default:codelibs", clauses.get(1).query().toString());