File nonExistentDir = new File(tempDir, "non_existent");
        execJob.testDeleteTempDir(nonExistentDir);
    }

    // Test appendJarFile method
    @Test
    public void test_appendJarFile() throws IOException {
        StringBuilder buf = new StringBuilder();
        File libDir = new File(tempDir, "lib");
        assertTrue(libDir.mkdir());

        // Create test jar files