* and pattern-based checks are performed.
 *
 * <p>If you know that a given string represents a numeric IP address, use {@link InetAddresses} to
 * obtain and manipulate a {@link java.net.InetAddress} instance from it rather than using this
 * class. Similarly, if you know that a given string represents a domain name, use {@link
 * InternetDomainName} rather than this class.
 *
 * @author Craig Berry
 * @since 5.0
 */
@J2ktIncompatible

    ```

=== "Python 3.10+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="11  13  20  23"
    {!> ../../../docs_src/background_tasks/tutorial002_py310.py!}
    ```

=== "Python 3.8+ non-Annotated"

    !!! tip
        Prefer to use the `Annotated` version if possible.

    ```Python hl_lines="13  15  22  25"

        that it's for a use case that actually comes up in the real world. We want to hear the
        real-world use case so the community can discuss and debate whether this feature is actually
        the *best* way to address the real use case, or whether or not a different approach might be
        more appropriate.


        It's okay if you can't provide complete context on a use case. We understand if you are not

    /**
     * @param message a message
     * @deprecated use {@link #ArtifactMetadataRetrievalException(String, Throwable, Artifact)}
     */
    @Deprecated
    public ArtifactMetadataRetrievalException(String message) {
        super(message, null, null);
    }

    /**
     * @param cause a cause
     * @deprecated use {@link #ArtifactMetadataRetrievalException(String, Throwable, Artifact)}
     */

 * com.google.common.reflect.TypeToInstanceMap} instead.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#classtoinstancemap">{@code
 * ClassToInstanceMap}</a>.
 *
 * @param <B> the common supertype that all values will share. When in doubt, just use {@link
 *     Object}, or use {@code @Nullable Object} to allow null values.

# Form Data

When you need to receive form fields instead of JSON, you can use `Form`.

!!! info
    To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

    E.g. `pip install python-multipart`.

## Import `Form`

Import `Form` from `fastapi`:

=== "Python 3.9+"

    ```Python hl_lines="3"

The following arguments are supported:

* `allow_origins` - A list of origins that should be permitted to make cross-origin requests. E.g. `['https://example.org', 'https://www.example.org']`. You can use `['*']` to allow any origin.

!!! info
    In this example we use invented custom headers `X-Key` and `X-Token`.

    But in real cases, when implementing security, you would get more benefits from using the integrated [Security utilities (the next chapter)](../security/index.md){.internal-link target=_blank}.

## Dependencies errors and return values

You can use the same dependency *functions* you use normally.

### Dependency requirements

 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * 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,

## Use case

For example, imagine that you want to return an HTTP status code of "OK" `200` by default.

But if the data didn't exist, you want to create it, and return an HTTP status code of "CREATED" `201`.

But you still want to be able to filter and convert the data you return with a `response_model`.

For those cases, you can use a `Response` parameter.

## Use a `Response` parameter