assertEquals(3, keySet.size());
        assertTrue(keySet.contains("key1"));
        assertTrue(keySet.contains("key2"));
        assertTrue(keySet.contains("key3"));
    }

    public void test_getKeySetEmpty() {
        // Test getKeySet on empty metadata
        ExtractData data = new ExtractData();

        Set<String> keySet = data.getKeySet();
        assertNotNull(keySet);