* cache-control headers.
     */
    open fun cacheControl(cacheControl: CacheControl): Builder = commonCacheControl(cacheControl)

    open fun get(): Builder = commonGet()

    open fun head(): Builder = commonHead()

    open fun post(body: RequestBody): Builder = commonPost(body)

    @JvmOverloads
    open fun delete(body: RequestBody? = commonEmptyRequestBody): Builder = commonDelete(body)

  <name>The Apache Software Foundation</name>
  <description>
    The Apache Software Foundation provides support for the Apache community of open-source software projects.
    The Apache projects are characterized by a collaborative, consensus based development process, an open and
    pragmatic software license, and a desire to create high quality software that leads the way in its field.

# CI Pipeline Configuration

## Open & import the project

In your IDEA, `File` - `Open`, select `.teamcity/pom.xml`, `import as project`, and you'll have a Maven project.

## Project structure

Mostly a standard Maven project structure. The entry point `settings.kts` defines the TeamCity project.

There are 3 subprojects in the TeamCity project hierarchy: `Check` for Gradle builds, `Promotion` for releasing Gradle versions, `Util` for miscellaneous utilities.

<div class="termy">

```console
$ fastapi dev main.py

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

</div>

Open your browser at <a href="http://127.0.0.1:8000" class="external-link" target="_blank">http://127.0.0.1:8000</a>.

You will see a simple page like:

<img src="/img/tutorial/websockets/image01.png">

    }
  }

  /**
   * Returns true if this stream is open. A stream is open until either:
   *
   *  * A `SYN_RESET` frame abnormally terminates the stream.
   *  * Both input and output streams have transmitted all data and headers.
   *
   * Note that the input stream may continue to yield data even after a stream reports itself as
   * not open. This is because input data is buffered.
   */
  val isOpen: Boolean

{!../../../docs_src/events/tutorial002.py!}
```

此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

!!! info "说明"

    `open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

!!! tip "提示"

    注意，本例使用 Python `open()` 标准函数与文件交互。

    这个函数执行 I/O（输入/输出）操作，需要等待内容写进磁盘。

    但 `open()` 函数不支持使用 `async` 与 `await`。

    因此，声明事件处理函数要使用 `def`，不能使用 `asnyc def`。

!!! info "说明"

이 예제에서 `shutdown` 이벤트 핸들러 함수는 `"Application shutdown"`이라는 텍스트가 적힌 `log.txt` 파일을 추가할 것입니다.

!!! info "정보"
    `open()` 함수에서 `mode="a"`는 "추가"를 의미합니다. 따라서 이미 존재하는 파일의 내용을 덮어쓰지 않고 새로운 줄을 추가합니다.

!!! tip "팁"
    이 예제에서는 파일과 상호작용 하기 위해 파이썬 표준 함수인 `open()`을 사용하고 있습니다.

    따라서 디스크에 데이터를 쓰기 위해 "대기"가 필요한 I/O (입력/출력) 작업을 수행합니다.

    그러나 `open()`은 `async`와 `await`을 사용하지 않기 때문에 이벤트 핸들러 함수는 `async def`가 아닌 표준 `def`로 선언하고 있습니다.

!!! info "정보"

```Python hl_lines="1  13"
{!../../../docs_src/events/tutorial003.py!}
```

Ein **Kontextmanager** in Python ist etwas, das Sie in einer `with`-Anweisung verwenden können, zum Beispiel kann `open()` als Kontextmanager verwendet werden:

```Python
with open("file.txt") as file:
    file.read()
```

In neueren Versionen von Python gibt es auch einen **asynchronen Kontextmanager**. Sie würden ihn mit `async with` verwenden:

```Python

```Python hl_lines="1  13"
{!../../../docs_src/events/tutorial003.py!}
```

Um **gerenciador de contexto** em Python é algo que você pode usar em uma declaração `with`, por exemplo, `open()` pode ser usado como um gerenciador de contexto:

```Python
with open("file.txt") as file:
    file.read()
```

Nas versões mais recentes de Python, há também um **gerenciador de contexto assíncrono**. Você o usaria com `async with`:

```Python

```Python hl_lines="1  13"
{!../../../docs_src/events/tutorial003.py!}
```

A **context manager** in Python is something that you can use in a `with` statement, for example, `open()` can be used as a context manager:

```Python
with open("file.txt") as file:
    file.read()
```

In recent versions of Python, there's also an **async context manager**. You would use it with `async with`:

```Python