//                                                                           Heartbeat
    //                                                                           =========

    /**
     * Sends a heartbeat document to OpenSearch to indicate this instance is active.
     */
    public void sendHeartbeat() {
        final long now = System.currentTimeMillis();

 * <ul>
 * <li>Retrieves crawled documents from the data service</li>
 * <li>Transforms document data using appropriate transformers</li>
 * <li>Applies document boosting rules and click/favorite count enhancements</li>
 * <li>Sends processed documents to the search engine for indexing</li>
 * <li>Manages cleanup of processed crawler session data</li>
 * </ul>
 *
 * <p>The updater runs continuously until crawling is finished and all documents are processed.

    public void test_isTarget() {
        // Test isTarget method
        generator = new TestThumbnailGenerator();
        Map<String, Object> docMap = new HashMap<>();

        // Note: isTarget requires FessConfig which needs container
        // We can only verify the method handles missing container gracefully
        try {
            generator.isTarget(docMap);
        } catch (IllegalStateException e) {

            writeJsonResponse(HttpServletResponse.SC_BAD_REQUEST, escapeJsonKeyValue(MESSAGE_FIELD, "Unsupported operation."));
            return;
        }

        final String seed = request.getParameter("seed");
        String[] tags = SearchRequestParams.getParamValueArray(request, "label");
        final String key = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        if (StringUtil.isNotBlank(key)) {

     */
    public void setStreamCloseTimeout(final int streamCloseTimeout) {
        this.streamCloseTimeout = streamCloseTimeout;
    }

    /**
     * Sends a command to the process associated with the given session ID.
     * Uses finer-grained locking to avoid blocking other operations during I/O.
     *
     * @param sessionId unique identifier for the process session

            setup.setup(form -> {
                updateForm(fessConfig, form);
            });
        });
    }

    /**
     * Sends a test mail using the provided notification settings.
     *
     * @param form the mail form containing notification settings
     * @return HTML response after sending test mail
     */
    @Execute

                    logger.warn("Failed to send error response. error={}", ioe.getMessage());
                }
            }
        }
    }

    /**
     * Sends a Server-Sent Event (SSE) to the client.
     *
     * @param writer the print writer to write the event to
     * @param event the event name
     * @param data the event data to serialize as JSON
     */

            final List<FunctionScoreQueryBuilder.FilterFunctionBuilder> flist = new ArrayList<>();
            flist.add(new FunctionScoreQueryBuilder.FilterFunctionBuilder(ScoreFunctionBuilders.randomFunction()
                    .seed(ComponentUtil.getSystemHelper().getCurrentTimeAsLong())
                    .setField(fessConfig.getIndexFieldDocId())));
            reader.setQuery(QueryBuilders

        },
        "alphanum_word_filter" : {
          "type" : "alphanum_word",
          "max_token_length" : 20
        },
        "minhash_filter" : {
          "type" : "minhash",
          "seed" : 1,
          "bit" : 2,
          "size" : 64
        },
        "synonym_filter" : {
          "type" : "synonym_graph",
          "synonyms_path": "${fess.dictionary.path}synonym.txt"
        }

     */
    public IndexingHelper() {
        // Default constructor
    }

    /** Interval between requests in milliseconds */
    protected long requestInterval = 500;

    /**
     * Sends a list of documents to the search engine for indexing.
     * This method handles thumbnail processing, deletes old documents with the same URL,
     * and performs bulk indexing operations with proper error handling.
     *