final Map<String, Object> document = indexingHelper.getDocument(client, "999", new String[] { "title" });
        assertNull(document);
    }

    @Test
    public void test_getDocumentListByQuery_withNullFields() {
        documentSizeByQuery = 1L;
        final Map<String, String> resultMap = new HashMap<>();
        final SearchEngineClient client = new SearchEngineClient() {
            @Override