Map<String, Object> docMap = new HashMap<>();
        docMap.put("_id", "docid1");

        // Fill the queue
        thumbnailManager.offer(docMap);

        // Try to add another - should succeed (warning logged but still returns true)
        Map<String, Object> docMap2 = new HashMap<>();
        docMap2.put("_id", "docid2");
        generator.task = new Tuple3<>("generator1", "docid2", "path2");

        sentIndex.set(null);
        sentDocList.clear();
        docList.add(new HashMap<>(Map.of(//
                "_id", "001", //
                "config_id", "W01", //
                "url", "http://test.com/001"//
        )));
        docList.add(new HashMap<>(Map.of(//
                "_id", "002", //
                "thumbnail", "http://test.com/002", //
                "url", "http://test.com/002"//
        )));

            logger.info("Token: {}", testToken);
            return testToken;
        }

        given().contentType("application/json")
                .body("{\"index\":{\"_index\":\"fess_config.access_token\",\"_id\":\"" + DEFAULT_TEST_TOKEN_ID

                        SearchEngineUtil.scroll(index, hit -> {
                            try {
                                writer.write("{\"index\":{\"_index\":\"" + index + "\",\"_id\":\""
                                        + StringEscapeUtils.escapeJson(hit.getId()) + "\"}}\n");
                                writer.write(hit.getSourceAsString());
                                writer.write("\n");

            @Override
            public String getIndexFieldContent() {
                return "content";
            }

            @Override
            public String getIndexFieldId() {
                return "_id";
            }

            @Override
            public String getIndexFieldDocId() {
                return "doc_id";
            }

            @Override
            public String getIndexFieldBoost() {

            public String getIndexFieldTimestamp() {
                return "timestamp";
            }

            @Override
            public String getIndexFieldId() {
                return "_id";
            }

            @Override
            public String getIndexFieldDocId() {
                return "doc_id";
            }

            @Override

        private transient RequestOptionCall<DeleteRequestBuilder> deleteOption;

        public DocMeta id(String id) {
            this.id = id;
            myuniqueByProperty("_id");
            return this;
        }

        public String id() {
            return id;
        }

        public DocMeta version(Long version) {
            this.version = version;

        JsonPath jsonPath = JsonPath.from(response.asString());
        String scrollId = jsonPath.getString("_scroll_id");
        while (true) {
            List<String> resultIds = jsonPath.getList("hits.hits._id");
            if (resultIds.size() == 0) {
                break;
            }
            docIds.addAll(resultIds);
            Map<String, Object> scrollBody = new HashMap<>();

            @Override
            public String getIndexFieldContent() {
                return "content";
            }

            @Override
            public String getIndexFieldId() {
                return "_id";
            }

            @Override
            public String getIndexFieldDocId() {
                return "doc_id";
            }

            @Override
            public String getIndexFieldBoost() {

        }

        @Override
        public String getIndexFieldDocId() {
            return "doc_id";
        }

        @Override
        public String getIndexFieldId() {
            return "_id";
        }

        @Override
        public String getIndexFieldVersion() {
            return "_version";
        }

        @Override
        public String getIndexFieldSeqNo() {