// Test multi-level exception chaining
        Exception level1 = new Exception("Level 1");
        RuntimeException level2 = new RuntimeException("Level 2", level1);
        StorageException level3 = new StorageException("Level 3", level2);

        assertEquals("Level 3", level3.getMessage());
        assertEquals(level2, level3.getCause());
        assertEquals("Level 2", level3.getCause().getMessage());

        // Test deeply nested exception causes
        Exception level3 = new Exception("Level 3: Database connection failed");
        Exception level2 = new Exception("Level 2: User lookup failed", level3);
        Exception level1 = new Exception("Level 1: Authentication service error", level2);
        SsoProcessException topLevel = new SsoProcessException("SSO process failed", level1);

        // Verify the chain

    public void test_multiLevelExceptionChain() {
        // Test multi-level exception chain
        Throwable level3 = new NullPointerException("Null value");
        Throwable level2 = new IllegalStateException("Invalid state", level3);
        Throwable level1 = new RuntimeException("Runtime error", level2);
        PluginException exception = new PluginException("Plugin failure", level1);

        // Verify the complete chain

        String template = "${level1.level2.value}";
        Map<String, Object> paramMap = new HashMap<>();
        Map<String, Object> level2 = new HashMap<>();
        level2.put("value", "nested");
        Map<String, Object> level1 = new HashMap<>();
        level1.put("level2", level2);
        paramMap.put("level1", level1);

        Object result = scriptEngine.evaluate(template, paramMap);

        // Test nested exception handling
        Exception level3 = new RuntimeException("Level 3 error");
        Exception level2 = new IllegalStateException("Level 2 error", level3);
        Exception level1 = new IOException("Level 1 error", level2);
        SsoLoginException exception = new SsoLoginException("Top level SSO error", level1);

        assertEquals("Top level SSO error", exception.getMessage());

        // Test with complex nested document structure
        Map<String, Object> doc = new HashMap<>();
        doc.put("id", "complex");

        Map<String, Object> nested = new HashMap<>();
        nested.put("level2", "value");
        doc.put("nested", nested);

        List<String> list = new ArrayList<>();
        list.add("item1");
        list.add("item2");
        doc.put("list", list);

   * Returns the ancestor of the current domain at the given number of levels "higher" (rightward)
   * in the subdomain list. The number of levels must be non-negative, and less than {@code N-1},
   * where {@code N} is the number of parts in the domain.
   *
   * <p>TODO: Reasonable candidate for addition to public API.
   */
  private InternetDomainName ancestor(int levels) {

    public void test_exceptionChaining() {
        // Test exception chaining with multiple levels
        Exception rootCause = new Exception("Root cause");
        RuntimeException middleCause = new RuntimeException("Middle cause", rootCause);
        FessSystemException topException = new FessSystemException("Top level", middleCause);

        assertEquals("Top level", topException.getMessage());
        assertEquals(middleCause, topException.getCause());

                .setLevel(Level.ERROR)
                .setMessage(new SimpleMessage("test message 3"))
                .build();

        LogEvent result1 = policy.rewrite(event1);
        LogEvent result2 = policy.rewrite(event2);
        LogEvent result3 = policy.rewrite(event3);

        assertEquals(Level.WARN, result1.getLevel());
        assertEquals(Level.WARN, result2.getLevel());

    assertThat(applicationInterceptor.level).isEqualTo(Level.NONE)
    for (level in Level.entries) {
      applicationInterceptor.setLevel(level)
      assertThat(applicationInterceptor.level).isEqualTo(level)
    }
  }

  @Test
  fun setLevelShouldReturnSameInstanceOfInterceptor() {
    for (level in Level.entries) {
      assertThat(applicationInterceptor.setLevel(level)).isSameInstanceAs(applicationInterceptor)
    }