*   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>
 * </ul>
 *
 * <p>The main purpose of {@link #addListener addListener} is to support this chaining. You will
 * rarely use it directly, in part because it does not provide direct access to the {@code Future}
 * result. (If you want such access, you may prefer {@link Futures#addCallback
 * Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *

<div class="termy">

```console
$ fastapi dev

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

Então, vá para a interface `/docs`, você verá que o **FastAPI** está usando esses **modelos** para **documentar** a API, e ele também os usará para **serializar** e **validar** os dados.

<div class="screenshot">
<img src="/img/tutorial/sql-databases/image01.png">

Você gosta do **FastAPI**?

Você gostaria de ajudar o FastAPI, outras pessoas usuárias e o autor?

Ou você gostaria de obter ajuda com o **FastAPI**?

Há maneiras muito simples de ajudar (várias envolvem apenas um ou dois cliques).

E também há várias formas de obter ajuda.

## Assine a newsletter { #subscribe-to-the-newsletter }

 * Splitter splitter = Splitter.on('/');
 * splitter.trimResults(); // does nothing!
 * return splitter.split("wrong / wrong / wrong");
 * }
 *
 * <p>For separator-based splitters that do not use {@code omitEmptyStrings}, an input string
 * containing {@code n} occurrences of the separator naturally yields an iterable of size {@code n +
 * 1}. So if the separator does not occur anywhere in the input, a single substring is returned

 *   <li><a href="https://dagger.dev/producers.html">Dagger Producers</a>
 * </ul>
 *
 * <p>The main purpose of {@link #addListener addListener} is to support this chaining. You will
 * rarely use it directly, in part because it does not provide direct access to the {@code Future}
 * result. (If you want such access, you may prefer {@link Futures#addCallback
 * Futures.addCallback}.) Still, direct {@code addListener} calls are occasionally useful:
 *

################################################################################
ARG BASE_IMAGE=ubuntu:22.04@sha256:445586e41c1de7dfda82d2637f5ff688deea9eb5f5812f8c145afacc35b9f0db
FROM $BASE_IMAGE AS devel
# See https://docs.docker.com/reference/dockerfile/#understand-how-arg-and-from-interact
# on why we cannot reference BASE_IMAGE again unless we declare it again.
################################################################################

Esse é o benefício dos padrões...

///

## Veja em ação { #see-it-in-action }

Abra o docs interativo: [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs).

### Autentique-se { #authenticate }

Clique no botão "Authorize".

Use as credenciais:

User: `johndoe`

And you get all the editor support with that resulting object.

An example from the official Pydantic docs:

{* ../../docs_src/python_types/tutorial011_py310.py *}

/// info

To learn more about [Pydantic, check its docs](https://docs.pydantic.dev/).

///

**FastAPI** is all based on Pydantic.

import org.jspecify.annotations.NonNull;
import org.jspecify.annotations.Nullable;

/**
 * An expanded {@code Iterable} API, providing functionality similar to Java 8's powerful <a href=
 * "https://docs.oracle.com/javase/8/docs/api/java/util/stream/package-summary.html#package.description"
 * >streams library</a> in a slightly different way.
 *
 * <p>The following types of methods are provided:
 *
 * <ul>

  public static int checkedMultiply(int a, int b) {
    return Math.multiplyExact(a, b);
  }

  /**
   * Returns the {@code b} to the {@code k}th power, provided it does not overflow.
   *
   * <p>{@link #pow} may be faster, but does not check for overflow.
   *
   * @throws ArithmeticException if {@code b} to the {@code k}th power overflows in signed {@code
   *     int} arithmetic
   */