assertNull(exception.getCause());
    }

    public void test_constructor_withSpecialCharacters() {
        // Test with username containing special characters
        String username = "******@****.***";
        FessUserNotFoundException exception = new FessUserNotFoundException(username);

        assertNotNull(exception);

        }

        // Check for control characters
        for (int i = 0; i < str.length(); i++) {
            char c = str.charAt(i);
            if (c < 0x20 && c != '\t' && c != '\r' && c != '\n') {
                failedValidations.incrementAndGet();
                log.warn("{} contains control characters", fieldName);
                throw new SmbException(fieldName + " contains control characters");
            }
        }
    }

    }

    // Test append with Unicode characters
    public void test_append_unicodeCharacters() {
        StringBuilder buf = new StringBuilder();
        Supplier<Object> supplier = () -> "テスト 测试 테스트 🎉";

        monitorTarget.append(buf, "unicodeKey", supplier);
        // Unicode characters are escaped in JSON format

        System.arraycopy(buffer, Smb2Constants.SMB2_HEADER_LENGTH + 8, actualPath, 0, pathBytes.length);
        assertArrayEquals(pathBytes, actualPath);
    }

    @Test
    @DisplayName("Should handle Unicode characters in path")
    void testUnicodePathHandling() throws Exception {
        // Given
        String unicodePath = "\\\\server\\共享文件夹\\テスト";

     *
     * @param ch the characters from the XML document
     * @param start the start position in the character array
     * @param length the number of characters to use from the character array
     * @throws SAXException if a SAX error occurs during character processing
     */
    @Override
    public void characters(final char[] ch, final int start, final int length) throws SAXException {

            assertFalse("Should return empty for locale: " + locale, result.isPresent());
        }
    }

    public void test_provide_withSpecialCharacters() {
        // Test classification names with special characters
        assertProvideThrowsException("Test@Classification");
        assertProvideThrowsException("Test#Classification");
        assertProvideThrowsException("Test$Classification");

        assertNull(user.getName());

        // Test with special characters in name
        user = new TestFessUser("******@****.***", new String[] {}, new String[] {}, new String[] {});
        assertEquals("******@****.***", user.getName());

        // Test with Unicode characters
        user = new TestFessUser("ユーザー名", new String[] {}, new String[] {}, new String[] {});

    private static final long serialVersionUID = 0;
  }

  /**
   * Creates a {@code HashCode} from a hexadecimal ({@code base 16}) encoded string. The string must
   * be at least 2 characters long, and contain only valid, lower-cased hexadecimal characters.
   *
   * <p>This method accepts the exact format generated by {@link #toString}. If you require more

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

    public void test_constructor_withSpecialCharactersInMessage() {
        // Test constructor with special characters in message
        final String message = "Job failed with special chars: \n\t\r\"'<>&";
        final JobProcessingException exception = new JobProcessingException(message);

        assertNotNull(exception);

        // NetBIOS names can be up to 15 characters
        String[] testNames = { "A", "SERVER", "LONGSERVERNAME", "EXACTLY15CHARS1" };

        for (String testName : testNames) {
            when(mockNetbiosName.getName()).thenReturn(testName);
            assertEquals(testName, mockNetbiosName.getName());
        }
    }

    @Test
    @DisplayName("Should handle special characters in names")
    void testSpecialCharacters() {