* `tags: List[str] = []` 默认值为一个空列表：`[]`。

但如果它们并没有被实际存储，你可能希望在结果中省略这些默认值。

例如，当你在 NoSQL 数据库中保存了具有许多可选属性的模型，但又不想发送充满默认值的冗长 JSON 响应。

### 使用 `response_model_exclude_unset` 参数 { #use-the-response-model-exclude-unset-parameter }

你可以设置*路径操作装饰器*参数 `response_model_exclude_unset=True`：

{* ../../docs_src/response_model/tutorial004_py310.py hl[22] *}

这样响应中将不会包含那些默认值，而只包含实际设置的值。

                }
              });
    }
  }

  @AfterExperiment
  void tearDown() throws Exception {
    executorService.shutdown();
  }

  @Footprint(exclude = {Runnable.class, Executor.class})
  public Object measureSize() {
    list = impl.newExecutionList();
    for (int i = 0; i < numListeners; i++) {
      list.add(listener, directExecutor());
    }

        Path mavenConf = mavenHome.resolve("conf");
        Files.createDirectories(mavenConf);
        Path mavenUserProps = mavenConf.resolve("maven-user.properties");
        Files.writeString(mavenUserProps, "${includes} = ?${session.rootDirectory}/.mvn/maven-user.properties\n");
        Path rootDirectory = fs.getPath("C:\\myRootDirectory");
        Path topDirectory = rootDirectory.resolve("myTopDirectory");

package okhttp3

import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertNull
import okhttp3.MediaType.Companion.toMediaTypeOrNull

/**
 * Test MediaType API and parsing.
 *
 * This test includes tests from [Guava's](https://code.google.com/p/guava-libraries/)
 * MediaTypeTest.
 */
open class MediaTypeTest {
  open fun MediaType.charsetName(): String? = parameter("charset")?.uppercase()

   * unprivileged user may return a resource accessible only to a privileged user making a similar
   * call. To prevent this problem, create a key object that includes all values that affect the
   * result of the query. Or use {@code LoadingCache.get(K)}, which lacks the ability to refer to
   * state other than that in the key.
   *

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded` when it doesn't include files.

But when the form includes files, it is encoded as `multipart/form-data`. If you use `File`, **FastAPI** will know it has to get the files from the correct part of the body.

   > "/${TARGET}/usr/lib64/libstdc++.so.${LIBSTDCXX_VERSION}"
cp "./x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/libstdc++_nonshared44.a" \
   "/${TARGET}/usr/lib64"
;;
esac

# Link in architecture specific includes from the system; note that we cannot
# link in the whole x86_64-linux-gnu folder, as otherwise we're overlaying
# system gcc paths that we do not want to find.
# TODO(klimek): Automate linking in all non-gcc / non-kernel include

        }).createPageNumberList());

        return webConfigList;
    }

    /**
     * Deletes a web configuration and all its related data.
     * This includes removing associated web authentications and request headers.
     *
     * @param webConfig The web configuration to delete
     */
    public void delete(final WebConfig webConfig) {

Cipher suites that are only available with TLSv1.3.

<a name="http2_naughty"></a>
#### ² HTTP/2 Cipher Suite Denylist

Cipher suites that are [discouraged for use][http2_denylist] with HTTP/2. OkHttp includes them because better suites are not commonly available. For example, none of the better cipher suites listed above shipped with Android 4.4 or Java 7.

[OkHttp30]: https://square.github.io/okhttp/changelog_3x/#version-300

## OAuth2 { #oauth2 }

OAuth2 is a specification that defines several ways to handle authentication and authorization.

It is quite an extensive specification and covers several complex use cases.

It includes ways to authenticate using a "third party".

That's what all the systems with "login with Facebook, Google, X (Twitter), GitHub" use underneath.

### OAuth 1 { #oauth-1 }