They tend to require more complex configurations, a message/job queue manager, like RabbitMQ or Redis, but they allow you to run background tasks in multiple processes, and especially, in multiple servers.

You can use it like this:

{* ../../docs_src/schema_extra_example/tutorial005_an_py310.py hl[23:49] *}

### OpenAPI Examples in the Docs UI { #openapi-examples-in-the-docs-ui }

With `openapi_examples` added to `Body()` the `/docs` would look like:

<img src="/img/tutorial/body-fields/image02.png">

## Technical Details { #technical-details }

    NetbiosAddress getNbtByName(String host, int type, String scope) throws UnknownHostException;

    /**
     * Determines the address of a host given it's host name. The name can be a NetBIOS name like
     * "freto" or an IP address like "192.168.1.15". It cannot be a DNS name;
     * the analygous {@link jcifs.netbios.UniAddress} or {@link java.net.InetAddress}
     * <code>getByName</code> methods can be used for that.
     *

        "name": "The Foo live"
    }
}
```

Again, doing just that declaration, with **FastAPI** you get:

* Editor support (completion, etc.), even for nested models
* Data conversion
* Data validation
* Automatic documentation

## Special types and validation { #special-types-and-validation }

    return result
  }
}

internal data class AlgorithmIdentifier(
  /** An OID string like "1.2.840.113549.1.1.11" for sha256WithRSAEncryption. */
  val algorithm: String,
  /** Parameters of a type implied by [algorithm]. */
  val parameters: Any?,
)

internal data class AttributeTypeAndValue(
  /** An OID string like "2.5.4.11" for organizationalUnitName. */
  val type: String,
  val value: Any?,
)

{* ../../docs_src/events/tutorial002.py hl[6] *}

Here, the `shutdown` event handler function will write a text line `"Application shutdown"` to a file `log.txt`.

/// info

In the `open()` function, the `mode="a"` means "append", so, the line will be added after whatever is on that file, without overwriting the previous contents.

///

/// tip

///

## Response Status Code { #response-status-code }

You can define the (HTTP) `status_code` to be used in the response of your *path operation*.

You can pass directly the `int` code, like `404`.

But if you don't remember what each number code is for, you can use the shortcut constants in `status`:

{* ../../docs_src/path_operation_configuration/tutorial001_py310.py hl[1,15] *}

{* ../../docs_src/websockets/tutorial003_py39.py hl[79:81] *}

To try it out:

* Open the app with several browser tabs.
* Write messages from them.
* Then close one of the tabs.

That will raise the `WebSocketDisconnect` exception, and all the other clients will receive a message like:

```
Client #1596980209979 left the chat
```

	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "fÄo!"))
	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "去是伟大的."))
	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), ""))
	fmt.Println(bytes.ContainsAny([]byte(""), ""))
	// Output:
	// true
	// true
	// false
	// false
}

func ExampleContainsRune() {
	fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'f'))

`secrets.compare_digest()` needs to take `bytes` or a `str` that only contains ASCII characters (the ones in English), this means it wouldn't work with characters like `á`, as in `Sebastián`.

To handle that, we first convert the `username` and `password` to `bytes` encoding them with UTF-8.