}

  private fun retryAfter(
    userResponse: Response,
    defaultDelay: Int,
  ): Int {
    val header = userResponse.header("Retry-After") ?: return defaultDelay

    // https://tools.ietf.org/html/rfc7231#section-7.1.3
    // currently ignores a HTTP-date, and assumes any non int 0 is a delay
    if (header.matches("\\d+".toRegex())) {
      return Integer.valueOf(header)
    }

    assertEquals(HashCode.fromBytes(mac.doFinal()), hashFunc.hashBytes(input));
    assertEquals(HashCode.fromBytes(mac.doFinal(input)), hashFunc.hashBytes(input));
  }

  // Tests from RFC2022: https://tools.ietf.org/html/rfc2202

  public void testRfc2202_hmacSha1_case1() {
    byte[] key = fillByteArray(20, 0x0b);
    String data = "Hi There";

    checkSha1("b617318655057264e28bc0b6fb378c8ef146be00", key, data);

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

///

## Dependencies with `yield`, `HTTPException`, `except` and Background Tasks { #dependencies-with-yield-httpexception-except-and-background-tasks }

/// warning

afterEvaluate {
  tasks.withType<Test> {
    if (javaLauncher.get().metadata.languageVersion.asInt() < 9) {
      // Work around robolectric requirements and limitations
      // https://cs.android.com/android-studio/platform/tools/base/+/mirror-goog-studio-main:build-system/gradle-core/src/main/java/com/android/build/gradle/tasks/factory/AndroidUnitTest.java;l=339
      allJvmArgs = allJvmArgs.filter { !it.startsWith("--add-opens") }
    }

За результатами опитувань розробників Python <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">однією з найпопулярніших функцій є "автодоповнення"</a>.

**FastAPI** повністю підтримує автодоповнення у всіх місцях, тому вам рідко доведеться повертатися до документації.

Dans le dernier sondage effectué auprès de développeurs python il était clair que <a href="https://www.jetbrains.com/research/python-developers-survey-2017/#tools-and-features" class="external-link" target="_blank">la fonctionnalité la plus utilisée est "l’autocomplétion"</a>.

Tout le framework **FastAPI** a été conçu avec cela en tête. L'autocomplétion fonctionne partout.

{* ../../docs_src/websockets/tutorial002.py hl[58:65,68:83] *}

/// info | 情報

WebSocket で `HTTPException` を発生させることはあまり意味がありません。したがって、WebSocketの接続を直接閉じる方がよいでしょう。

クロージングコードは、<a href="https://tools.ietf.org/html/rfc6455#section-7.4.1" class="external-link" target="_blank">仕様で定義された有効なコード</a>の中から使用することができます。

     * the server responds with `HTTP/1.0`, that will be exposed by [Response.protocol].
     *
     * [alpn]: http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg
     * [rfc_2616]: http://www.w3.org/Protocols/rfc2616/rfc2616.html
     * [rfc_7540]: https://tools.ietf.org/html/rfc7540
     * [rfc_7540_34]: https://tools.ietf.org/html/rfc7540#section-3.4
     *

  }
}

/**
 * Returns the string "OkHttp" unless the library has been shaded for inclusion in another library,
 * or obfuscated with tools like R8 or ProGuard. In such cases it'll return a longer string like
 * "com.example.shaded.okhttp3.OkHttp". In large applications it's possible to have multiple OkHttp
 * instances; this makes it clear which is which.
 */

Das ist besonders nützlich, wenn Sie es in einer **großen Codebasis** verwenden, in der Sie in **vielen *Pfadoperationen*** immer wieder **dieselben Abhängigkeiten** verwenden.