*       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless
 *       of the type argument supplied by the user of the class: For example, {@code

 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless
 *       of the type argument supplied by the user of the class: For example, {@code

 *       typically because the type forbids nullable type arguments: For example, {@code
 *       ImmutableList.get} returns {@code E}, but that value is never {@code null}. (Accordingly,
 *       {@code ImmutableList} is declared to forbid {@code ImmutableList<@Nullable String>}.)
 *   <li>methods whose return type is a type variable but which can return {@code null} regardless
 *       of the type argument supplied by the user of the class: For example, {@code

import com.google.common.base.Function;
import java.util.concurrent.Executor;
import org.jspecify.annotations.Nullable;

/**
 * Hidden superclass of {@link FluentFuture} that provides us a place to declare special GWT
 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */

  private static WildcardType canonicalizeWildcardType(
      TypeVariable<?> declaration, WildcardType type) {
    Type[] declared = declaration.getBounds();
    List<Type> upperBounds = new ArrayList<>();
    for (Type bound : type.getUpperBounds()) {
      if (!any(declared).isSubtypeOf(bound)) {
        upperBounds.add(canonicalizeWildcardsInType(bound));
      }
    }

Dessa forma, você diz ao editor que está retornando qualquer coisa intencionalmente. Mas o FastAPI ainda fará a documentação de dados, validação, filtragem, etc. com o `response_model`.

///

### Prioridade `response_model` { #response-model-priority }

Use base64 only if you definitely need to include binary data in JSON, and you can't use files for that.

## Pydantic `bytes` { #pydantic-bytes }

You can declare a Pydantic model with `bytes` fields, and then use `val_json_bytes` in the model config to tell it to use base64 to *validate* input JSON data, as part of that validation it will decode the base64 string into bytes.

## Импорт `Header` { #import-header }

Сперва импортируйте `Header`:

{* ../../docs_src/header_params/tutorial001_an_py310.py hl[3] *}

## Объявление параметров `Header` { #declare-header-parameters }

Затем объявите параметры заголовка, используя ту же структуру, что и с `Path`, `Query` и `Cookie`.

    private String language;

    @Deprecated
    private boolean addedToClasspath;

    /**
     * Default ctor for Plexus compatibility, as many plugins have artifact handlers declared in legacy Plexus XML.
     * Do not use directly!
     *
     * @deprecated This ctor is present only for Plexus XML defined component compatibility, do not use it.
     */
    @Deprecated

import com.google.common.base.Function;
import java.util.concurrent.Executor;
import org.jspecify.annotations.Nullable;

/**
 * Hidden superclass of {@link Futures} that provides us a place to declare special GWT versions of
 * the {@link Futures#catching(ListenableFuture, Class, com.google.common.base.Function)
 * Futures.catching} family of methods. Those versions have slightly different signatures.
 */