public void test_Read() throws Exception {
        String indexName = "test-index";
        Client client = runner.client();
        SuggestSettings settings = suggester.settings();
        int num = 10000;

        addDocument(indexName, client, num);

        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(1000);
        int count = 0;