// Index suggestions from existing Elasticsearch documents
DocumentReader reader = new ESSourceReader(
    client,
    suggester.settings(),
    "content-index",        // source index
    "document"             // document type
);

suggester.indexer()
    .indexFromDocument(reader, 2, 100)  // threads=2, batch=100
    .getResponse();
```

### Index from Query Logs

```java

Shinsuke Sugaya <******@****.***> 1756618372 +0900

        /**
         * Constructor.
         * @param reader The reader.
         */
        public TextNormalizeContext(final Reader reader) {
            this.reader = reader;
        }

        /**
         * Executes the text processing operation on the provided reader.
         *
         * This method reads characters from the reader and processes them according to the following rules:

 * String indexName = "your_index_name";
 *
 * ESSourceReader reader = new ESSourceReader(client, settings, indexName);
 * reader.setScrollSize(1000); // Set the scroll size
 * reader.setLimitOfDocumentSize(1024 * 1024); // Limit document size to 1MB
 * reader.setQuery(QueryBuilders.termQuery("field", "value")); // Set a query
 *
 * Map<String, Object> document;
 * while ((document = reader.read()) != null) {
 *     // Process the document

            if (!dfos.isInMemory()) {
                tempFile = dfos.getFile();
            }

            try (Reader reader = new InputStreamReader(getContentStream(dfos), enc)) {
                if (normalizeText) {
                    return TextUtil.normalizeText(reader)
                            .initialCapacity(initialBufferSize)
                            .maxAlphanumTermSize(maxAlphanumTermSize)

            throw new SuggestIndexException("Failed to index from query_string.", e);
        }
    }

    /**
     * Indexes documents from a query log reader asynchronously.
     * @param queryLogReader The query log reader.
     * @param docPerReq The number of documents to process per request.
     * @param requestInterval The interval between requests.

        CountDownLatch latch = new CountDownLatch(1);
        AtomicInteger numObInputDoc = new AtomicInteger(0);
        ESSourceReader reader = new ESSourceReader(client, suggester.settings(), indexName);
        reader.setScrollSize(1000);

        suggester.indexer().indexFromDocument(() -> reader, 1000, () -> ThreadUtil.sleep(100)).then(response -> {
            numObInputDoc.set(response.getNumberOfInputDocs());

                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                }
            }
        });

        Thread reader = new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    statusSetLatch.countDown();