// 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

        addDocument(indexName, client, num);

        ESSourceReader reader = new ESSourceReader(client, settings, indexName);
        reader.setScrollSize(1);
        reader.setLimitDocNumPercentage("1%");
        int count = 0;
        Set<String> valueSet = Collections.synchronizedSet(new HashSet<>());
        Map<String, Object> source;
        while ((source = reader.read()) != null) {

        if (value == null || value.length() == 0) {
            replacement = '\u30fc';
        } else {
            replacement = value.charAt(0);
        }
    }

    @Override
    public Reader create(final Reader tokenStream) {
        return new ProlongedSoundMarkCharFilter(tokenStream, replacement);
    }

        normalizeKana = settings.getAsBoolean("normalize_kana", JapaneseIterationMarkCharFilter.NORMALIZE_KANA_DEFAULT);
    }

    @Override
    public Reader create(Reader reader) {
        return new JapaneseIterationMarkCharFilter(reader, normalizeKanji, normalizeKana);
    }

        /**
         * 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:

        }
    }

    private Reader getReader(final boolean reload) throws IOException {
        if (reload) {
            if (reloadableFile == null) {
                throw new IllegalArgumentException("reloadableFile is null.");
            }
            return new InputStreamReader(new FileInputStream(reloadableFile), StandardCharsets.UTF_8);
        }

        Reader reader = null;

            final File suffixWordsFile = environment.configDir().resolve(suffixWordsPath).toFile();
            try (Reader reader = IOUtils.getDecodingReader(new FileInputStream(suffixWordsFile), StandardCharsets.UTF_8)) {
                suffixWords = WordlistLoader.getWordSet(reader);
            } catch (final IOException e) {

            final Settings settings) {
        super(indexSettings, name);
    }

    @Override
    public Reader create(final Reader tokenStream) {
        return new IterationMarkCharFilter(tokenStream);
    }

 * 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