```

=== "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"

SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

!!! tip
    For new code and whenever possible, use `Annotated` as explained above. There are multiple advantages (explained below) and no disadvantages. 🍰

                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by

                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by

        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

It is designed to be very simple to use, and to make it very easy for any developer to integrate other components with **FastAPI**.

## What is "Dependency Injection"

**"Dependency Injection"** means, in programming, that there is a way for your code (in this case, your *path operation functions*) to declare things that it requires to work and use: "dependencies".

    /**
     * @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)}
     */

        str,
        Doc(
            """
            The URL to use to load the Swagger UI JavaScript.

            It is normally set to a CDN URL.
            """
        ),
    ] = "https://cdn.jsdelivr.net/npm/swagger-ui-dist@5.9.0/swagger-ui-bundle.js",
    swagger_css_url: Annotated[
        str,
        Doc(
            """
            The URL to use to load the Swagger UI CSS.

            It is normally set to a CDN URL.

 * 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.