### Events with Retries and Follow-Ups

OkHttp is resilient and can automatically recover from some connectivity failures. In this case, the `connectFailed()` event is not terminal and not followed by `callFailed()`. Event listeners will receive multiple events of the same type when retries are attempted.

 * [RFC 2817][1]. The HTTP CONNECT request that creates this tunnel connection is special: it
 * does not participate in any [interceptors][Interceptor] or [event listeners][EventListener]. It
 * doesn't include the motivating request's HTTP headers or even its full URL; only the target
 * server's hostname is sent to the proxy.
 *

    Listener listener;
    synchronized (this) {
      listener = listeners.get(state);
    }

    if (code == null || listener == null) {
      return new MockResponse()
          .setResponseCode(404)
          .setBody("unexpected request");
    }

    try {
      OAuthSession session = slackApi.exchangeCode(code, redirectUrl());
      listener.sessionGranted(session);

     * [Request.tag]. Use null to remove any existing tag assigned for [T].
     *
     * Use this API to attach timing, debugging, or other application data to a request so that
     * you may read it in interceptors, event listeners, or callbacks.
     */
    @JvmName("reifiedTag")
    inline fun <reified T : Any> tag(tag: T?): Builder = tag(T::class, tag)

    /**

import org.junit.platform.launcher.core.LauncherConfig
import org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder
import org.junit.platform.launcher.core.LauncherFactory
import org.junit.platform.launcher.listeners.SummaryGeneratingListener

/**
 * Graal main method to run tests with minimal reflection and automatic settings.
 * Uses the test list in native-image-tests/src/main/resources/testlist.txt.
 */

    return EventSource.Factory { request, listener ->
      val actualRequest =
        if (request.header("Accept") == null) {
          request.newBuilder().addHeader("Accept", "text/event-stream").build()
        } else {
          request
        }

      RealEventSource(actualRequest, listener).apply {
        connect(callFactory)
      }
    }
  }

  @JvmStatic

     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be
     * notified. The caller must cancel the returned event source when it is no longer in use.
     */
    fun newEventSource(
      request: Request,
      listener: EventSourceListener,
    ): EventSource
  }

  @RegisterExtension
  @JvmField
  var clientTestRule = OkHttpClientTestRule()

  private val listener = RecordingEventListener()
  private val handshakeCertificates = platform.localhostHandshakeCertificates()

  private var client =
    clientTestRule.newClientBuilder()
      .eventListenerFactory(clientTestRule.wrap(listener))
      .build()

  private lateinit var server: MockWebServer

  @BeforeEach

    }
  }

  /** See https://api.slack.com/rtm. */
  public WebSocket rtm(HttpUrl url, WebSocketListener listener) {
    return httpClient.newWebSocket(new Request.Builder()
        .url(url)
        .build(), listener);
  }

  static final class SlackJsonAdapters {
    @ToJson String urlToJson(HttpUrl httpUrl) {
      return httpUrl.toString();
    }

  private var protocol: Protocol?,
  private var source: BufferedSource?,
  private var sink: BufferedSink?,
  private val pingIntervalMillis: Int,
  internal val connectionListener: ConnectionListener,
) : Http2Connection.Listener(), Connection, ExchangeCodec.Carrier {
  private var http2Connection: Http2Connection? = null

  internal val lock: ReentrantLock = ReentrantLock()

  // These properties are guarded by [lock].

  /**