mutableTags[type] = type.cast(tag)
        }
      }

    /** Attaches [tag] to the request using `Object.class` as a key. */
    open fun tag(tag: Any?): Builder = tag(Any::class, tag)

    /**
     * Attaches [tag] to the request using [type] as a key. Tags can be read from a
     * request using [Request.tag]. Use null to remove any existing tag assigned for [type].
     *

This gives you a lot of flexibility. You can return any data type, override any data declaration or validation, etc.

## Using the `jsonable_encoder` in a `Response` { #using-the-jsonable-encoder-in-a-response }

Because **FastAPI** doesn't make any changes to a `Response` you return, you have to make sure its contents are ready for it.

  protected SetTestSuiteBuilder<K> createDerivedKeySetSuite(TestSetGenerator<K> keySetGenerator) {
    return keySetGenerator instanceof TestSortedSetGenerator
        ? SortedSetTestSuiteBuilder.using((TestSortedSetGenerator<K>) keySetGenerator)
        : SetTestSuiteBuilder.using(keySetGenerator);
  }

  /**
   * To avoid infinite recursion, test suites with these marker features won't have derived suites
   * created for them.
   */

 * @author Louis Wasserman
 */
@GwtIncompatible
public class SetMultimapTestSuiteBuilder<K, V>
    extends MultimapTestSuiteBuilder<K, V, SetMultimap<K, V>> {

  public static <K, V> SetMultimapTestSuiteBuilder<K, V> using(
      TestSetMultimapGenerator<K, V> generator) {
    SetMultimapTestSuiteBuilder<K, V> result = new SetMultimapTestSuiteBuilder<>();
    result.usingGenerator(generator);
    return result;
  }

 * <ul>
 *   <li>Build sources: Used for POM files of projects being built by Maven in the filesystem.
 *       These sources support resolving related POMs using the {@link ModelLocator}.</li>
 *   <li>Resolved sources: Used for artifacts that have been resolved by Maven from repositories
 *       (using groupId:artifactId:version coordinates) and downloaded to the local repository.
 *       These sources do not support resolving other sources.</li>
 * </ul>

        // Restore system properties and clean up static state
        System.setProperties(originalSystemProperties);
        resetHandlerState();
    }

    /**
     * Resets the static state of the Handler class using reflection.
     * This is crucial for ensuring that tests are isolated from each other.
     */
    private void resetHandlerState() throws Exception {
        // Reset the static factory field

 * @author Louis Wasserman
 */
@GwtIncompatible
public class SetMultimapTestSuiteBuilder<K, V>
    extends MultimapTestSuiteBuilder<K, V, SetMultimap<K, V>> {

  public static <K, V> SetMultimapTestSuiteBuilder<K, V> using(
      TestSetMultimapGenerator<K, V> generator) {
    SetMultimapTestSuiteBuilder<K, V> result = new SetMultimapTestSuiteBuilder<>();
    result.usingGenerator(generator);
    return result;
  }

            ListTestSuiteBuilder.using(new DoublesAsListGenerator()).named("Doubles.asList"),
            ListTestSuiteBuilder.using(new DoublesAsListHeadSubListGenerator())
                .named("Doubles.asList, head subList"),
            ListTestSuiteBuilder.using(new DoublesAsListTailSubListGenerator())
                .named("Doubles.asList, tail subList"),
            ListTestSuiteBuilder.using(new DoublesAsListMiddleSubListGenerator())

query_extractor(["query_extractor"])
query_or_cookie_extractor(["query_or_cookie_extractor"])

read_query["/items/"]

query_extractor --> query_or_cookie_extractor --> read_query
```

## Using the same dependency multiple times { #using-the-same-dependency-multiple-times }

///

## **FastAPI** utilities { #fastapi-utilities }

FastAPI provides several tools for each of these security schemes in the `fastapi.security` module that simplify using these security mechanisms.

In the next chapters you will see how to add security to your API using those tools provided by **FastAPI**.