},
                    "type": "object",
                    "required": ["name", "price"],
                    "title": "Item",
                    "examples": [
                        {
                            "name": "Foo",
                            "description": "A very nice Item",
                            "price": 35.4,
                            "tax": 3.2,

* Aplicar regras de segurança, autenticação, papéis de usuários, etc.
* E muitas outras coisas...

Tudo isso, enquanto minimizamos a repetição de código.

## Primeiros passos

Vamos ver um exemplo simples. Tão simples que não será muito útil, por enquanto.

Mas dessa forma podemos focar em como o sistema de **Injeção de Dependência** funciona.

### Criando uma dependência, ou "injetável"

   * convenient.
   *
   * <p>By default, a {@code Builder} will generate bimaps that iterate over entries in the order
   * they were inserted into the builder. For example, in the above example, {@code
   * WORD_TO_INT.entrySet()} is guaranteed to iterate over the entries in the order {@code "one"=1,
   * "two"=2, "three"=3}, and {@code keySet()} and {@code values()} respect the same order. If you

    @Override
    protected FessUserBean createUserBean(final FessUser user) {
        return new FessUserBean(user);
    }

    @Override
    protected OptionalThing<String> getCookieRememberMeKey() {
        // example to use remember-me
        //return OptionalThing.of(fessConfig.getCookieRememberMeFessKey());
        return OptionalThing.empty();
    }

    @Override

## `TrustedHostMiddleware`

强制所有传入请求都必须正确设置 `Host` 请求头，以防 HTTP 主机头攻击。

```Python hl_lines="2  6-8"
{!../../docs_src/advanced_middleware/tutorial002.py!}
```

支持以下参数：

* `allowed_hosts` - 允许的域名（主机名）列表。`*.example.com` 等通配符域名可以匹配子域名，或使用 `allowed_hosts=["*"]` 允许任意主机名，或省略中间件。

如果传入的请求没有通过验证，则发送 `400` 响应。

## `GZipMiddleware`

处理 `Accept-Encoding` 请求头中包含 `gzip` 请求的 GZip 响应。

中间件会处理标准响应与流响应。

```Python hl_lines="2  6"

Pero en algunos casos necesitas retornar un status code diferente al predeterminado.

## Casos de uso

Por ejemplo, imagina que quieres retornar un HTTP status code de "OK" `200` por defecto.

Pero si los datos no existen, quieres crearlos y retornar un HTTP status code de "CREATED" `201`.

      shell: bash
      run: |
        echo 'If you are using a "manual" build mode for one or more of the' \
          'languages you are analyzing, replace this with the commands to build' \
          'your code, for example:'
        echo '  make bootstrap'
        echo '  make release'
        exit 1

    - name: Perform CodeQL Analysis
      uses: github/codeql-action/analyze@v3
      with:

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Abstract implementation of {@link InvocationHandler} that handles {@link Object#equals}, {@link
 * Object#hashCode} and {@link Object#toString}. For example:
 *
 * <pre>
 * class Unsupported extends AbstractInvocationHandler {
 *   protected Object handleInvocation(Object proxy, Method method, Object[] args) {
 *     throw new UnsupportedOperationException();
 *   }
 * }

 * breadth first traversal) that only need a way of accessing the successors of a node in a graph.
 *
 * <h3>Usage</h3>
 *
 * Given an algorithm, for example:
 *
 * <pre>{@code
 * public <N> someGraphAlgorithm(N startNode, SuccessorsFunction<N> successorsFunction);
 * }</pre>
 *
 * you will invoke it depending on the graph representation you're using.
 *

 * annotated by {@link TestSubtype}.
 *
 * <p>These declaration methods rely on Java static type checking to make sure what we want to
 * assert as subtypes are really subtypes according to javac. For example:
 *
 * <pre>{@code
 * class MySubtypeTests extends SubtypeTester {
 *   @TestSubtype(suppressGetSubtype = true, suppressGetSupertype = true)
 *   public <T> Iterable<? extends T> listIsSubtypeOfIterable(List<T> list) {