*
 * To perform server authentication:
 *
 *  * The server's handshake certificates must have a [held certificate][HeldCertificate] (a
 *    certificate and its private key). The certificate's subject alternative names must match the
 *    server's hostname. The server must also have is a (possibly-empty) chain of intermediate
 *    certificates to establish trust from a root certificate to the server's certificate. The root

A common tool is <a href="https://openapi-generator.tech/" class="external-link" target="_blank">OpenAPI Generator</a>.

If you are building a **frontend**, a very interesting alternative is <a href="https://github.com/hey-api/openapi-ts" class="external-link" target="_blank">openapi-ts</a>.

## Client and SDK Generators - Sponsor

    builder.setUnsafeReplacement("\uFFFD");

    /*
     * Except for \n, \t, and \r, all ASCII control characters are replaced with the Unicode
     * replacement character.
     *
     * Implementation note: An alternative to the following would be to make a map that simply
     * replaces the allowed ASCII whitespace characters with themselves and to set the minimum safe

func ConfigureLogging(_ *cobra.Command, _ []string) error {
	return log.Configure(root.LoggingOptions)
}

// seeExperimentalCmd is used for commands that have been around for a release but not graduated from
// Other alternative
// for graduatedCmd see https://github.com/istio/istio/pull/26408
// for softGraduatedCmd see https://github.com/istio/istio/pull/26563
func seeExperimentalCmd(name string) *cobra.Command {

            sb.append(" -Dfile=/path/to/file");
            sb.append(LS);

            // If people want to deploy it
            sb.append(LS);
            sb.append(indentation);
            sb.append("Alternatively, if you host your own repository you can deploy the file there: ");
            sb.append(LS);
            sb.append(indentation);
            sb.append("    mvn deploy:deploy-file -DgroupId=");

```

////

//// tab | Python 3.8+

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009.py!}
```

////

//// tab | Python 3.8+ alternative

```Python hl_lines="1  4"
{!> ../../docs_src/python_types/tutorial009b.py!}
```

////

#### Using `Union` or `Optional`

Este é um caso de uso mais avançado. Sinta-se à vontade para pular.

///

Por padrão, o **FastAPI** criará um `server` no OpenAPI schema com o URL para o `root_path`.

Mas você também pode fornecer outros `servers` alternativos, por exemplo, se quiser que a *mesma* interface de documentação interaja com ambientes de staging e produção.

    // in the opposite order from how they were added so we need to reverse the list to fulfill our
    // contract.
    // This is somewhat annoying, but turns out to be very fast in practice. Alternatively, we could
    // drop the contract on the method that enforces this queue like behavior since depending on it
    // is likely to be a bug anyway.

   * href="http://download.oracle.com/javase/7/docs/api/java/util/concurrent/atomic/package-summary.html#Spurious">
   * fail spuriously</a> and does not provide ordering guarantees, so is only rarely an appropriate
   * alternative to {@code compareAndSet}.
   *
   * @param i the index
   * @param expect the expected value
   * @param update the new value
   * @return true if successful
   */

Ela é importada/incluída diretamente no FastAPI para que você possa importá-la do `fastapi` e evitar a importação acidental da alternativa `BackgroundTask` (sem o `s` no final) de `starlette.background`.