///

{* ../../docs_src/extra_models/tutorial003_py310.py hl[1,14:15,18:20,33] *}

### `Union` in Python 3.10 { #union-in-python-3-10 }

In this example we pass `Union[PlaneItem, CarItem]` as the value of the argument `response_model`.

There's a whole chapter here in the documentation about it, you can read it at [Additional Responses in OpenAPI](additional-responses.md){.internal-link target=_blank}.

## OpenAPI Extra { #openapi-extra }

When you declare a *path operation* in your application, **FastAPI** automatically generates the relevant metadata about that *path operation* to be included in the OpenAPI schema.

/// note | Technical details

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,

     *
     * @param dst the destination byte array to encode into
     * @param dstIndex the starting index in the destination array
     * @return encoded length
     */
    int encode(byte[] dst, int dstIndex);

    /**
     * Returns the size in bytes that this object will occupy when encoded.
     *
     * @return the encoded size
     */
    int size();

 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,

 * Copyright (C) 2022 Square, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

	limit := dirent.Reclen - fixedHdr
	if limit > nameBufLen {
		limit = nameBufLen
	}
	// Avoid bugs in long file names
	// https://github.com/golang/tools/commit/5f9a5413737ba4b4f692214aebee582b47c8be74
	nameLen := bytes.IndexByte(nameBuf[:limit], 0)
	if nameLen < 0 {
		return 0, fmt.Errorf("failed to find terminating 0 byte in dirent")
	}
	return uint64(nameLen), nil

Hier übergeben wir `examples`, welches ein einzelnes Beispiel für die in `Body()` erwarteten Daten enthält:

{* ../../docs_src/schema_extra_example/tutorial003_an_py310.py hl[22:29] *}

### Beispiel in der Dokumentations-Benutzeroberfläche { #example-in-the-docs-ui }

Mit jeder der oben genannten Methoden würde es in `/docs` so aussehen:

<img src="/img/tutorial/body-fields/image01.png">