}

    /**
     * Test concurrent reads from deleteUrlList while synchronized.
     * Verifies that ArrayList can be safely read when properly synchronized.
     */
    @Test
    public void test_deleteUrlList_concurrentReads() throws Exception {
        IndexUpdateCallback mockCallback = new IndexUpdateCallback() {
            @Override
            public void store(DataStoreParams paramMap, Map<String, Object> dataMap) {