import java.util.Spliterator;
import java.util.Spliterators;
import java.util.Spliterators.AbstractSpliterator;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Consumer;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
import java.util.stream.BaseStream;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;

import java.util.Spliterator;
import java.util.Spliterators;
import java.util.Spliterators.AbstractSpliterator;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Consumer;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
import java.util.stream.BaseStream;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;

import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *
 * @since NEXT (but since 21.0 in the JRE flavor)

import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.Spliterator;
import java.util.Spliterator.OfPrimitive;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tester for {@code Spliterator} implementations.
 *

 *     the same lambda function as passed into {@link #using(Function)}.
 *     <p>This class is scheduled to be removed in October 2019.
 */
// TODO(b/68134636): Remove by 2019-10
@Deprecated
@Beta
@GwtCompatible
@ElementTypesAreNonnullByDefault
public abstract class TreeTraverser<T> {

  /**
   * Returns a tree traverser that uses the given function to navigate from a node to its children.

import org.opensearch.action.get.GetRequestBuilder;
import org.opensearch.action.get.GetResponse;
import org.opensearch.action.get.MultiGetRequest;
import org.opensearch.action.get.MultiGetRequestBuilder;
import org.opensearch.action.get.MultiGetResponse;
import org.opensearch.action.index.IndexRequest;
import org.opensearch.action.index.IndexRequestBuilder;
import org.opensearch.action.index.IndexResponse;
import org.opensearch.action.search.ClearScrollRequest;

By default, what the method `.openapi()` does is check the property `.openapi_schema` to see if it has contents and return them.

If it doesn't, it generates them using the utility function at `fastapi.openapi.utils.get_openapi`.

And that function `get_openapi()` receives as parameters:

* `title`: The OpenAPI title, shown in the docs.
* `version`: The version of your API, e.g. `2.5.0`.

In this case, the task function will write to a file (simulating sending an email).

And as the write operation doesn't use `async` and `await`, we define the function with normal `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Add the background task

Dans cet exemple, la fonction de tâche écrira dans un fichier (afin de simuler un envoi d'email).

L'opération d'écriture n'utilisant ni `async` ni `await`, on définit la fonction avec un `def` normal.

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Ajouter une tâche d'arrière-plan

Next, we create a custom subclass of `fastapi.routing.APIRoute` that will make use of the `GzipRequest`.

This time, it will overwrite the method `APIRoute.get_route_handler()`.

This method returns a function. And that function is what will receive a request and return a response.

Here we use it to create a `GzipRequest` from the original request.

{* ../../docs_src/custom_request_and_route/tutorial001.py hl[18:26] *}