* <ul>
 * <li>os.name: The operating system name</li>
 * <li>os.arch: The operating system architecture</li>
 * <li>os.version: The operating system version</li>
 * </ul>
 * <p>
 * Supported OS families include:
 * <ul>
 * <li>windows: All Windows variants</li>
 * <li>win9x: Windows 95, 98, ME, CE</li>
 * <li>winnt: Windows NT variants</li>
 * <li>unix: Unix-like systems (including Linux)</li>

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.
 * Keep whichever TCP connection succeeds first and cancel all the others.

| Params     | Value    |
| :--        | :--      |
| *Type*     | *String* |
| *Required* | *Yes*    |

### AUTHPARAMS

Indicates STS API Authorization information. If you are familiar with AWS Signature V4 Authorization header, this STS API supports signature V4 authorization as mentioned [here](https://docs.aws.amazon.com/general/latest/gr/signature-version-4.html)

### DurationSeconds

~~ under the License.

 -----
 Inheritance in Maven
 -----
 The Maven Team
 -----

Inheritance in Maven

 In order the understand how inheritance works in Maven there are a few notions that you must be familiar with:

 * The maven super model

 * how parent poms are processed

 * the order in which elements in the POM are overridden

 * minimum element-set for a valid project pom


Maven super model

It is based on <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, which in turn is designed based on Requests, so it's very familiar and intuitive.

With it, you can use <a href="https://docs.pytest.org/" class="external-link" target="_blank">pytest</a> directly with **FastAPI**.

## Using `TestClient` { #using-testclient }

/// info

Está basado en <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, que a su vez está diseñado basado en Requests, por lo que es muy familiar e intuitivo.

Con él, puedes usar <a href="https://docs.pytest.org/" class="external-link" target="_blank">pytest</a> directamente con **FastAPI**.

## Usando `TestClient` { #using-testclient }

/// info | Información

Ele é baseado no <a href="https://www.python-httpx.org" class="external-link" target="_blank">HTTPX</a>, que por sua vez é projetado com base em Requests, por isso é muito familiar e intuitivo.

Com ele, você pode usar o <a href="https://docs.pytest.org/" class="external-link" target="_blank">pytest</a> diretamente com **FastAPI**.

## Usando `TestClient` { #using-testclient }

/// info | Informação

It will have a *path operation* that will receive an `Invoice` body, and a query parameter `callback_url` that will contain the URL for the callback.

This part is pretty normal, most of the code is probably already familiar to you:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip

Ele terá uma *operação de rota* que receberá um corpo `Invoice`, e um parâmetro de consulta `callback_url` que conterá a URL para o callback.

Essa parte é bastante normal, a maior parte do código provavelmente já é familiar para você:

{* ../../docs_src/openapi_callbacks/tutorial001_py310.py hl[7:11,34:51] *}

/// tip | Dica