private void createTestJarWithXml(File jarFile, String xmlContent) throws Exception {
        try (JarOutputStream jos = new JarOutputStream(new FileOutputStream(jarFile))) {
            JarEntry entry = new JarEntry("fess_ds++.xml");
            jos.putNextEntry(entry);
            jos.write(xmlContent.getBytes());
            jos.closeEntry();
        }
    }

    // Test DataStore implementation for testing