private static final Escaper HTML_ESCAPER =
      Escapers.builder()
          .addEscape('"', """)
          // Note: "'" is not defined in HTML 4.01.
          .addEscape('\'', "'")
          .addEscape('&', "&")
          .addEscape('<', "&lt;")
          .addEscape('>', "&gt;")
          .build();

  private HtmlEscapers() {}

    MavenExecutionRequest setExecutionListener(ExecutionListener executionListener);

    ProjectBuildingRequest getProjectBuildingRequest();

    /**
     * @since 3.1
     * @deprecated Since 3.9 there is no direct Maven2 interop offered at LRM level. See
     * <a href="https://maven.apache.org/resolver/configuration.html">Resolver Configuration</a> page option

      + "O1KzKtvn1ISMY/YPyyYBkVBs9F8U4pN0wBOeMDpQ47RgxRzwIkSNcUesyBrJ6Zua\n"
      + "AGAT/3B+XxFNSRuzFVJ7yVTav52Vr2ua2J7p8eRDjeIRRDq/r72DQnNSi6q7pynP\n"
      + "9WQcCk3RvKqsnyrQ/39/2n3qse0wJcGE2jTSW3iDVuycNsMm4hH2Z0kdkquM++v/\n"
      + "eu6FSqdQgPCnXEqULl8FmTxSQeDNtGPPAUO6nIPcj2A781q0tHuu2guQOHXvgR1m\n"
      + "0vdXcDazv/wor3ElhVsT/h5/WrQ8\n"
      + "-----END CERTIFICATE-----\n");

  val okHttp_4_10 = historicOkHttp("4.10")
  val okHttp_3_14 = historicOkHttp("3.14")
  val okHttp_3_13 = historicOkHttp("3.13")
  val okHttp_3_11 = historicOkHttp("3.11")
  val okHttp_3_9 = historicOkHttp("3.9")

  val currentVm = currentVm(ianaSuitesNew)

  val conscrypt =
    if (includeConscrypt) {
      Security.addProvider(Conscrypt.newProvider())
      conscrypt(ianaSuitesNew)
    } else {

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

What we will do is wrap that with `Annotated`, so it becomes:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python
q: Annotated[Union[str, None]] = None
```

////

**FastAPI** 知道在每种情况下该做什么以及如何复用同一对象，因此所有后台任务被合并在一起并且随后在后台运行：

//// tab | Python 3.10+

{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13, 15, 22, 25] *}

////

//// tab | Python 3.9+

{* ../../docs_src/background_tasks/tutorial002_an_py39.py hl[13, 15, 22, 25] *}

////

//// tab | Python 3.8+

{* ../../docs_src/background_tasks/tutorial002_an.py hl[14, 16, 23, 26] *}

////

jobs:
  test:
    strategy:
      matrix:
        os: [ windows-latest, macos-latest ]
        python-version: [ "3.14" ]
        include:
          - os: ubuntu-latest
            python-version: "3.9"
            coverage: coverage
          - os: macos-latest
            python-version: "3.10"
            coverage: coverage
          - os: windows-latest
            python-version: "3.12"

    A4IBAQCT1DCw1wMgKtD5Y+iRDAUgqV8ZyntyTtSx29CW+1RaGSwMCPeyvIWonX9t
    O1KzKtvn1ISMY/YPyyYBkVBs9F8U4pN0wBOeMDpQ47RgxRzwIkSNcUesyBrJ6Zua
    AGAT/3B+XxFNSRuzFVJ7yVTav52Vr2ua2J7p8eRDjeIRRDq/r72DQnNSi6q7pynP
    9WQcCk3RvKqsnyrQ/39/2n3qse0wJcGE2jTSW3iDVuycNsMm4hH2Z0kdkquM++v/
    eu6FSqdQgPCnXEqULl8FmTxSQeDNtGPPAUO6nIPcj2A781q0tHuu2guQOHXvgR1m
    0vdXcDazv/wor3ElhVsT/h5/WrQ8
    -----END CERTIFICATE-----
    """.trimIndent().decodeCertificatePem()

有个 `POST` 操作会返回一些错误。

所有*路径操作* 都需要一个`X-Token` 头。

//// tab | Python 3.10+

```Python
{!> ../../docs_src/app_testing/app_b_an_py310/main.py!}
```

////

//// tab | Python 3.9+

```Python
{!> ../../docs_src/app_testing/app_b_an_py39/main.py!}
```

////

//// tab | Python 3.8+

```Python
{!> ../../docs_src/app_testing/app_b_an/main.py!}
```

////

/// note | Nota

FastAPI sabrá que el valor de `q` no es requerido debido al valor por defecto `= None`.

El `str | None` (Python 3.10+) o `Union` en `Union[str, None]` (Python 3.9+) no es utilizado por FastAPI para determinar que el valor no es requerido, sabrá que no es requerido porque tiene un valor por defecto de `= None`.