// All should be the same promise instance
        assertEquals("Promise chain should return same instance", promise1, promise2);
        assertEquals("Promise chain should return same instance", promise2, promise3);
    }

    @Test
    public void test_promiseFromDeferredThen() throws Exception {

        AtomicReference<Throwable> errorRef = new AtomicReference<>();

        Deferred<SuggestIndexResponse>.Promise promise = suggester.indexer().indexFromQueryLog(emptyReader, 10, 0);

        promise.then(response -> {
            responseRef.set(response);
            latch.countDown();
        }).error(error -> {
            errorRef.set(error);

     */
    public Request() {
        // nothing
    }

    /**
     * Executes the request.
     * @param client The OpenSearch client.
     * @return A Promise that will be resolved with the response or rejected with an error.
     */
    public Deferred<T>.Promise execute(final Client client) {
        final String error = getValidationError();
        if (!Strings.isNullOrEmpty(error)) {

     * @param docPerReq The number of documents to process per request
     * @param requestInterval The interval between requests
     * @return A Promise that will be resolved with the SuggestIndexResponse
     */
    public Deferred<SuggestIndexResponse>.Promise indexFromQueryLog(final ContentIndexingContext ctx, final QueryLogReader queryLogReader,
            final int docPerReq, final long requestInterval) {

     * @param docPerReq The number of documents to process per request.
     * @param requestInterval The interval between requests.
     * @return A Promise that will be resolved with the SuggestIndexResponse or rejected with an error.
     */
    public Deferred<SuggestIndexResponse>.Promise indexFromQueryLog(final QueryLogReader queryLogReader, final int docPerReq,
            final long requestInterval) {
        ensureOperations();

├── concurrent/                 # Async patterns (Deferred/Promise)
└── util/                      # Utilities
```

### Key Design Patterns

- **Builder**: SuggesterBuilder, SuggestRequestBuilder
- **Facade**: Suggester (main entry point)
- **Composite**: NormalizerChain, ReadingConverterChain
- **Strategy**: Normalizer, ReadingConverter, ContentsParser
- **Deferred/Promise**: Async operations

### Index Alias Strategy

       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain
       * nulls in its first `n` elements.
       */
      System.arraycopy(elements, 0, contents, size, n);
      size += n;

    if(!announceRight) return;

    const sponsorImages = document.querySelectorAll('.sponsor-image');

    const imagePromises = Array.from(sponsorImages).map(img => {
        return new Promise((resolve, reject) => {
            if (img.complete && img.naturalHeight !== 0) {
                resolve();
            } else {
                img.addEventListener('load', () => {

      weight: Int,
      exclusive: Boolean,
    )

    /**
     * HTTP/2 only. Receive a push promise header block.
     *
     * A push promise contains all the headers that pertain to a server-initiated request, and a
     * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent
     * as a part of the response to `streamId`.
     *

This policy protects our limited review budget, allowing us to invest our attention wisely.

A pull request is not a finished product—it is the start of a conversation, and an implied contract: we promise to provide thoughtful feedback, and we expect the contributor to engage with us in return.

## What we expect from contributors