*
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(predicate).findFirst()}.
   */
  public final Optional<@NonNull E> firstMatch(Predicate<? super E> predicate) {
    // Unsafe, but we can't do much about it now.
    return Iterables.<@NonNull E>tryFind((Iterable<@NonNull E>) getDelegate(), predicate);
  }

  /**
   * Returns a fluent iterable that applies {@code function} to each element of this fluent

   *
   * <p><b>{@code Stream} equivalent:</b> {@code stream.filter(predicate).findFirst()}.
   */
  public final Optional<@NonNull E> firstMatch(Predicate<? super E> predicate) {
    // Unsafe, but we can't do much about it now.
    return Iterables.<@NonNull E>tryFind((Iterable<@NonNull E>) getDelegate(), predicate);
  }

  /**
   * Returns a fluent iterable that applies {@code function} to each element of this fluent

Having the return model ensure that a value is always available and always `int` (not `None`) is very useful for the API clients, they can write much simpler code having this certainty.

Also, **automatically generated clients** will have simpler interfaces, so that the developers communicating with your API can have a much better time working with your API. 😎

///

    assert response.status_code == 200, response.text
    assert response.json() == data


def test_model_with_tuple_invalid():
    data = {"items": [["foo", "bar"], ["baz", "whatelse", "too", "much"]]}
    response = client.post("/model-with-tuple/", json=data)
    assert response.status_code == 422, response.text

    data = {"items": [["foo", "bar"], ["baz"]]}
    response = client.post("/model-with-tuple/", json=data)

      if (useBarriers) {
        firstBarrier.await();
        secondBarrier.await();
      }
    }

    @Override
    protected ScheduledExecutorService executor() {
      // use a bunch of threads so that weird overlapping schedules are more likely to happen.
      return newScheduledThreadPool(10);
    }

    @Override
    protected Scheduler scheduler() {
      return new CustomScheduler() {

      if (useBarriers) {
        firstBarrier.await();
        secondBarrier.await();
      }
    }

    @Override
    protected ScheduledExecutorService executor() {
      // use a bunch of threads so that weird overlapping schedules are more likely to happen.
      return newScheduledThreadPool(10);
    }

    @Override
    protected Scheduler scheduler() {
      return new CustomScheduler() {

 *       does it offer a way to batch multiple events from a single producer together.
 *   <li>It doesn't support backpressure and other features needed for resilience.
 *   <li>It doesn't provide much control of threading.
 *   <li>It doesn't offer much monitoring.
 *   <li>It doesn't propagate exceptions, so apps don't have a way to react to them.
 *   <li>It doesn't interoperate well with RxJava, coroutines, and other more commonly used

Many packages that simplify it a lot have to make many compromises with the data model, database, and available features. And some of these packages that simplify things too much actually have security flaws underneath.

---

**FastAPI** doesn't make any compromise with any database, data model or tool.

It gives you all the flexibility to choose the ones that fit your project the best.

This would be even more important with large or infinite streams.

///

/// tip

Instead of returning a `StreamingResponse` directly, you should probably follow the style in [Stream Data](./stream-data.md), it's much more convenient and handles cancellation behind the scenes for you.

If you are streaming JSON Lines, follow the [Stream JSON Lines](../tutorial/stream-json-lines.md) tutorial.

///

curl -XDELETE localhost:9200/test

# insert a document
curl -XPUT localhost:9200/test/test/1 -d '{
 "title": "test document"
}'

# this should return XXXX but instead returns YYY
curl ....
```

Provide as much information as you can. You may think that the problem lies with your query, when actually it depends on how your data is indexed. The easier it is for us to recreate your problem, the faster it is likely to be fixed.

Feature requests