有些情况下，您可能想告诉您的 API **用户**，您的应用程序可以携带一些数据调用*他们的*应用程序（给它们发送请求），通常是为了**通知**某种**事件**。

这意味着，与通常由您的用户向您的 API 发送请求的流程相反，是**您的 API**（或您的应用）可以**向他们的系统**（他们的 API、他们的应用）**发送请求**。

这通常被称为**网络钩子**（Webhook）。

## 使用网络钩子的步骤 { #webhooks-steps }

通常的过程是**您**在代码中**定义**要发送的消息，即**请求的主体**。

您还需要以某种方式定义您的应用程序将在**何时**发送这些请求或事件。

**用户**会以某种方式（例如在某个网页仪表板上）定义您的应用程序发送这些请求应该使用的 **URL**。

所有关于注册网络钩子的 URL 的**逻辑**以及发送这些请求的实际代码都由您决定。您可以在**自己的代码**中以任何想要的方式来编写它。

* `http://localhost`
* `https://localhost`
* `http://localhost:8080`

Hepsi `localhost` üzerinde olsa bile, farklı protocol veya port kullandıkları için farklı "origin" sayılırlar.

## Adımlar { #steps }

 */

@NullUnmarked
@GwtIncompatible
@J2ktIncompatible
public class AbstractFutureFallbackAtomicHelperTest extends TestCase {

  // stash these in static fields to avoid loading them over and over again (speeds up test
  // execution significantly)

  /**
   * This classloader disallows {@link java.lang.invoke.VarHandle}, which will prevent us from
   * selecting the {@code VarHandleAtomicHelper} strategy.
   */

With fast fallback, OkHttp attempts to connect to multiple web servers concurrently. It keeps whichever route connects first and cancels all of the others. Its rules are:

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.

/// note | 기술 세부사항

`async` 작업은 `await`에 도달했을 때만 취소될 수 있습니다. `await`가 없으면 제너레이터(`yield`가 있는 함수)는 제대로 취소될 수 없고, 취소가 요청된 후에도 계속 실행될 수 있습니다.

이 작은 예제는 어떤 `await`도 필요하지 않으므로, 이벤트 루프가 취소를 처리할 기회를 주기 위해 `await anyio.sleep(0)`를 추가합니다.

대규모 또는 무한 스트림에서는 더욱 중요합니다.

///

/// tip | 팁

`StreamingResponse`를 직접 반환하는 대신, [데이터 스트리밍](./stream-data.md)에서의 스타일을 따르는 것이 더 편리하며 백그라운드에서 취소 처리를 해줍니다.

 * behavior of the stopwatch.
 *
 * <p><b>Note:</b> This class is not thread-safe.
 *
 * <p><b>Warning for Android users:</b> a stopwatch with default behavior may not continue to keep
 * time while the device is asleep. Instead, create one like this:
 *
 * {@snippet :
 * Stopwatch.createStarted(
 *      new Ticker() {
 *        public long read() {
 *          return android.os.SystemClock.elapsedRealtimeNanos();
 *        }

        NullPointerException.class, () -> multimap().putAll(k3(), newArrayList(null, v3())));

    /*
     * In principle, a Multimap implementation could add e3 first before failing on the null. But
     * that seems unlikely enough to be worth complicating the test over, especially if there's any
     * chance that a permissive test could mask a bug.
     */
    expectUnchanged();

	db, err := OpenTestConnection(&gorm.Config{DefaultTransactionTimeout: 2 * time.Second})
	if err != nil {
		t.Fatalf("failed to connect database, got error %v", err)
	}

	tx := db.Begin()
	time.Sleep(3 * time.Second)
	if err = tx.Find(&User{}).Error; err == nil {
		t.Errorf("should return error when transaction timeout, got error %v", err)
	}

     */
    // NB: yes, this is surprisingly high, but that's what the experiments said was necessary
    // Raising this number slows the worst-case contains behavior, speeds up hashFloodingDetected,
    // and reduces the false-positive probability.
    static final int MAX_RUN_MULTIPLIER = 13;

    /**

    }

    private Map<String, Lifecycle> lookupLifecycles() {
        // TODO: Remove the following code when maven-compat is gone
        // This code is here to ensure maven-compat's EmptyLifecycleExecutor keeps on working.
        if (lookup == null) {
            return customLifecycles != null ? customLifecycles : new HashMap<>();
        }