private var serverSocket: ServerSocket? = null

  @BeforeEach fun setUp() {
    executorService = Executors.newCachedThreadPool(threadFactory("HandshakeCertificatesTest"))
  }

  @AfterEach fun tearDown() {
    executorService.shutdown()
    serverSocket?.closeQuietly()
  }

  @Test fun clientAndServer() {
    platform.assumeNotConscrypt()
    platform.assumeNotBouncyCastle()

    val clientRoot =

    server.initWebSocket(random)
  }

  @AfterEach
  @Throws(Exception::class)
  fun tearDown() {
    client.listener.assertExhausted()
    server.listener.assertExhausted()
    server.source.close()
    client.source.close()
    taskFaker.runTasks()
    server.webSocket!!.tearDown()
    client.webSocket!!.tearDown()
    taskFaker.close()
  }

  @Test
  fun close() {

  private val metadata: ByteString = "great metadata!".encodeUtf8()
  private lateinit var file: File

  @BeforeEach
  fun setUp() {
    file = File(tempDir, "test")
  }

  @AfterEach
  fun tearDown() {
    executor.shutdown()
  }

  @Test
  fun singleSource() {
    val upstream = Buffer()
    upstream.writeUtf8("abcdefghijklm")
    val relay = edit(file, upstream, metadata, 1024)

  private val addressB = factory.newAddress("b")
  private val routeB1 = factory.newRoute(addressB)
  private val addressC = factory.newAddress("c")
  private val routeC1 = factory.newRoute(addressC)

  @AfterEach fun tearDown() {
    factory.close()
    peer.close()
  }

  @Test fun connectionsEvictedWhenIdleLongEnough() {
    val pool = factory.newConnectionPool()
    val c1 = factory.newConnection(pool, routeA1, 50L)

# 使用yield的依赖项

FastAPI支持在完成后执行一些<abbr title='有时也被称为“退出”("exit")，“清理”("cleanup")，“拆卸”("teardown")，“关闭”("close")，“上下文管理器”("context managers")。 ...'>额外步骤</abbr>的依赖项.

为此，请使用 `yield` 而不是 `return`，然后再编写额外的步骤（代码）。

!!! tip "提示"
    确保只使用一次 `yield` 。

!!! note "技术细节"

    任何一个可以与以下内容一起使用的函数：

    * <a href="https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager" class="external-link" target="_blank">`@contextlib.contextmanager`</a> 或者

   */
  private val routePlanner = FakeRoutePlanner(taskFaker = taskFaker)
  private val finder = FastFallbackExchangeFinder(routePlanner, taskRunner)

  @AfterEach
  fun tearDown() {
    taskFaker.close()
    routePlanner.close()
  }

  @Test
  fun takeConnectedConnection() {
    val plan0 = routePlanner.addPlan()
    plan0.connectState = TLS_CONNECTED

  private val log = mutableListOf<String>()
  private val redQueue = taskRunner.newQueue()
  private val blueQueue = taskRunner.newQueue()
  private val greenQueue = taskRunner.newQueue()

  @AfterEach
  internal fun tearDown() {
    taskFaker.close()
  }

  @Test fun executeDelayed() {
    redQueue.execute("task", 100.µs) {
      log += "run@${taskFaker.nanoTime}"
    }

    taskFaker.advanceUntil(0.µs)

# 🔗 ⏮️ 🌾

FastAPI 🐕‍🦺 🔗 👈 <abbr title='sometimes also called "exit", "cleanup", "teardown", "close", "context managers", ...'>➕ 🔁 ⏮️ 🏁</abbr>.

👉, ⚙️ `yield` ↩️ `return`, &amp; ✍ ➕ 🔁 ⏮️.

!!! tip
    ⚒ 💭 ⚙️ `yield` 1️⃣ 👁 🕰.

!!! note "📡 ℹ"
    🙆 🔢 👈 ☑ ⚙️ ⏮️:

    * <a href="https://docs.python.org/3/library/contextlib.html#contextlib.contextmanager" class="external-link" target="_blank">`@contextlib.contextmanager`</a> ⚖️

# yieldを持つ依存関係

FastAPIは、いくつかの<abbr title='時々"exit"、"cleanup"、"teardown"、"close"、"context managers"、 ...のように呼ばれる'>終了後の追加のステップ</abbr>を行う依存関係をサポートしています。

これを行うには、`return`の代わりに`yield`を使い、その後に追加のステップを書きます。

!!! tip "豆知識"
    `yield`は必ず一度だけ使用するようにしてください。

!!! info "情報"
    これを動作させるには、**Python 3.7** 以上を使用するか、**Python 3.6** では"backports"をインストールする必要があります:

    ```
    pip install async-exit-stack async-generator
    ```

    client =
      clientTestRule.newClientBuilder()
        .cache(cache)
        .cookieJar(JavaNetCookieJar(cookieManager))
        .build()
  }

  @AfterEach
  fun tearDown() {
    ResponseCache.setDefault(null)
    cache.delete()
  }

  /**
   * Test that response caching is consistent with the RI and the spec.
   * http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.4