@Execute
    @Secured({ ROLE, ROLE + VIEW })
    public HtmlResponse index() {
        saveToken();
        return asListHtml();
    }

    /**
     * Displays the failure URL list page with pagination support.
     *
     * @param pageNumber the page number to display
     * @param form the search form containing filter criteria
     * @return HTML response for the failure URL list page
     */
    @Execute

		return "", gcsToObjectError(err, gcs.Bucket, key)
	}

	if _, err := xioutil.Copy(w, data); err != nil {
		return "", gcsToObjectError(err, gcs.Bucket, key)
	}

	return "", w.Close()
}

// FIXME: add support for remote version ID in GCS remote tier and remove this.
// Currently it's a no-op.
func (gcs *warmBackendGCS) Put(ctx context.Context, key string, data io.Reader, length int64) (remoteVersionID, error) {

   *
   * <p><b>Warning:</b> do not call this method from Android code unless you are on Android API
   * level 26+ or you <a
   * href="https://developer.android.com/studio/write/java11-default-support-table">opt in to
   * library desugaring</a>.
   *
   * @since 33.4.0 (but since 22.0 in the JRE flavor)
   */
  // If users use this when they shouldn't, we hope that NewApi will catch subsequent Duration calls

    Class<?> rawType = type.getRawType();
    Object defaultValue = ArbitraryInstances.get(rawType);
    if (defaultValue != null) {
      return defaultValue;
    }

    // TODO(cpovirk): Support these types in ArbitraryInstances itself?
    if (rawType.equals(Predicate.class)) {
      return (Predicate<Object>) v -> (boolean) getDefaultValue(TypeToken.of(boolean.class));
    } else if (rawType.equals(IntFunction.class)) {

 *     return createExpensiveGraph(key);
 *   }
 * };
 * LoadingCache<Key, Graph> cache = CacheBuilder.newBuilder().build(loader);
 * }
 *
 * <p>Since this example doesn't support reloading or bulk loading, if you're able to use lambda
 * expressions it can be specified even more easily:
 *
 * {@snippet :
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }

                    } catch (DestroyFailedException e) {
                        // Log but continue - not all JVM implementations support destroying SecretKey
                        log.debug("SecretKey destroy not fully supported: {}", e.getMessage());
                        failedToDestroy = true;
                        destroyException = e;
                    }
                }

    }
  }

  // TODO: test adding element of wrong type

  /**
   * Returns {@link Method} instances for the {@code setCount()} tests that assume multisets support
   * duplicates so that the test of {@code Multisets.forSet()} can suppress them.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection
  public static List<Method> getSetCountDuplicateInitializingMethods() {

 *     return createExpensiveGraph(key);
 *   }
 * };
 * LoadingCache<Key, Graph> cache = CacheBuilder.newBuilder().build(loader);
 * }
 *
 * <p>Since this example doesn't support reloading or bulk loading, it can also be specified much
 * more simply:
 *
 * {@snippet :
 * CacheLoader<Key, Graph> loader = CacheLoader.from(key -> createExpensiveGraph(key));
 * }
 *
 * @author Charles Fry

 * <ul>
 *   <li><strong>Unsupported combine.children Attributes</strong>: Changes 'override' to 'merge' (Maven 4 only supports 'append' and 'merge')</li>
 *   <li><strong>Unsupported combine.self Attributes</strong>: Changes 'append' to 'merge' (Maven 4 only supports 'override', 'merge', and 'remove')</li>
 *   <li><strong>Duplicate Dependencies</strong>: Removes duplicate dependency declarations that Maven 4 strictly validates</li>

つまり、Pydantic v2 の最新バージョンをインストールし、このサブモジュールから旧 Pydantic v1 のコンポーネントをインポートして、あたかも v1 をインストールしているかのように使用できます。

{* ../../docs_src/pydantic_v1_in_v2/tutorial001_an_py310.py hl[1,4] *}

### v2 内の Pydantic v1 に対する FastAPI のサポート { #fastapi-support-for-pydantic-v1-in-v2 }

FastAPI 0.119.0 以降では、移行を容易にするため、Pydantic v2 内の Pydantic v1 に対する部分的サポートもあります。

そのため、Pydantic を v2 の最新に上げ、インポートを `pydantic.v1` サブモジュールに切り替えるだけで、多くの場合そのまま動作します。