@Test
public void testFromJar_useCacheDirectory() throws Exception {

    buildDeepTestJar();
    final File cacheDir = new File("target/test-output/OpearFileTest/testFromJar_useCacheDirectory/cache");
    if (cacheDir.exists()) {
        FileUtils.deleteDirectory(cacheDir);
    }
    assertTrue("succeed with jar when cache is fresh",
            OpearFile.fromJar(new JarFile(deepTestTarget), cacheDir).isSuccess());
    assertTrue("succeed with cache dir when cache is present",
            OpearFile.fromJar(new JarFile(deepTestTarget), cacheDir).isSuccess());
}