Und Sie können auch Body-Parameter als optional kennzeichnen, indem Sie den Defaultwert auf `None` setzen:

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note | Hinweis

Beachten Sie, dass in diesem Fall das `item`, welches vom Body genommen wird, optional ist. Da es `None` als Defaultwert hat.

///

## Mehrere Body-Parameter

And you can also declare body parameters as optional, by setting the default to `None`:

{* ../../docs_src/body_multiple_params/tutorial001_an_py310.py hl[18:20] *}

/// note

Notice that, in this case, the `item` that would be taken from the body is optional. As it has a `None` default value.

///

## Multiple body parameters { #multiple-body-parameters }

   *     network
   * @since 23.0
   */
  Optional<E> edgeConnecting(N nodeU, N nodeV);

  /**
   * Returns the single edge that directly connects {@code endpoints} (in the order, if any,
   * specified by {@code endpoints}), if one is present, or {@code Optional.empty()} if no such edge
   * exists.
   *
   * <p>If this network is directed, the endpoints must be ordered.

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.graph.Graphs.checkNonNegative;

import com.google.common.annotations.Beta;
import com.google.common.base.Optional;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/**
 * A builder for constructing instances of {@link MutableValueGraph} or {@link ImmutableValueGraph}
 * with user-defined properties.
 *

    if (allowsNullKeys) {
      boolean unused = map.containsKey(null);
    } else {
      try {
        boolean unused2 = map.containsKey(null);
      } catch (NullPointerException optional) {
      }
    }
    assertInvariants(map);
  }

  public void testContainsValue() {
    Map<K, V> map;
    V unmappedValue;
    try {
      map = makePopulatedMap();

* パラメータが **Pydantic モデル**型で宣言された場合、リクエスト**ボディ**として解釈されます。

/// note | 備考

FastAPIは、`= None`があるおかげで、`q`がオプショナルだとわかります。

`Optional[str]` の`Optional` はFastAPIでは使用されていません（FastAPIは`str`の部分のみ使用します）。しかし、`Optional[str]` はエディタがコードのエラーを見つけるのを助けてくれます。

///

## Pydanticを使わない方法

import org.codelibs.fess.dict.kuromoji.KuromojiItem;
import org.codelibs.fess.util.ComponentUtil;
import org.codelibs.fess.util.RenderDataUtil;
import org.dbflute.optional.OptionalEntity;
import org.dbflute.optional.OptionalThing;
import org.lastaflute.web.Execute;
import org.lastaflute.web.response.ActionResponse;
import org.lastaflute.web.response.HtmlResponse;
import org.lastaflute.web.response.render.RenderData;

        default:
            break;
        }
        return null;
    }

    /**
     * Creates an HTML response for the list page with optional pre-processing.
     *
     * @param runnable optional runnable to execute before rendering (can be null)
     * @return HTML response for the search request list page
     */
    private HtmlResponse asListHtml(final Runnable runnable) {

    // Test constructor
    public void test_constructor() {
        CorsFilter filter = new CorsFilter();
        assertNotNull(filter);
    }

    // Test OPTIONS constant
    public void test_optionsConstant() {
        assertEquals("OPTIONS", CorsFilter.OPTIONS);
    }

    // Helper classes for testing

    private static class TestCorsHandlerFactory extends CorsHandlerFactory {

import com.github.ajalt.clikt.parameters.arguments.help
import com.github.ajalt.clikt.parameters.options.default
import com.github.ajalt.clikt.parameters.options.flag
import com.github.ajalt.clikt.parameters.options.help
import com.github.ajalt.clikt.parameters.options.multiple
import com.github.ajalt.clikt.parameters.options.option
import com.github.ajalt.clikt.parameters.types.int
import java.security.cert.X509Certificate