override val timestampNs: Long,
    val route: Route,
    val call: Call,
  ) : ConnectionEvent()

  data class ConnectFailed(
    override val timestampNs: Long,
    val route: Route,
    val call: Call,
    val exception: IOException,
  ) : ConnectionEvent() {
    override fun closes(event: ConnectionEvent): Boolean = event is ConnectStart && call == event.call && route == event.route
  }

  data class ConnectEnd(

 *
 * Other exception types cancel the current call:
 *
 *  * For synchronous calls made with [Call.execute], the exception is propagated to the caller.
 *
 *  * For asynchronous calls made with [Call.enqueue], an [IOException] is propagated to the caller
 *    indicating that the call was canceled. The interceptor's exception is delivered to the current

    check(rawSocket == null) { "TCP already connected" }

    var success = false

    // Tell the call about the connecting call so async cancels work.
    call.plansToCancel += this
    try {
      call.eventListener.connectStart(call, route.socketAddress, route.proxy)
      connectionPool.connectionListener.connectStart(route, call)

      connectSocket()
      success = true
      return ConnectResult(plan = this)

  }

  @Override public void callStart(Call call) {
    printEvent("callStart");
  }

  @Override public void callEnd(Call call) {
    printEvent("callEnd");
  }

  @Override public void dnsStart(Call call, String domainName) {
    printEvent("dnsStart");
  }

  @Override public void dnsEnd(Call call, String domainName, List<InetAddress> inetAddressList) {
    printEvent("dnsEnd");

        .trailersDelay(1, TimeUnit.SECONDS)
        .build(),
    )

    val call = client.newCall(Request(server.url("/")))
    call.execute().use { response ->
      val source = response.body.source()
      assertThat(response.header("h1")).isEqualTo("v1")
      assertThat(source.readUtf8(5)).isEqualTo("Hello")
      call.cancelLater(500.milliseconds)
      val trailersDelay =
        measureTime {

        .build()

    val startNanos = System.nanoTime()
    val call = client.newCall(request)

    // Schedule a job to cancel the call in 1 second.
    executor.schedule({
      System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f)
      call.cancel()
      System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f)
    }, 1, TimeUnit.SECONDS)

        localhostIpv4,
        localhostIpv6,
      )
    serverIpv4.enqueue(
      MockResponse(body = "unexpected call to IPv4"),
    )
    serverIpv6.enqueue(
      MockResponse(body = "hello from IPv6"),
    )

    val call = client.newCall(Request(url))
    val response = call.execute()
    assertThat(response.body.string()).isEqualTo("hello from IPv6")

        override fun requestHeadersEnd(
          call: Call,
          request: Request,
        ) = TODO()

        override fun requestBodyStart(call: Call) = TODO()

        override fun requestBodyEnd(
          call: Call,
          byteCount: Long,
        ) = TODO()

        override fun requestFailed(
          call: Call,
          ioe: IOException,

      .tag(Integer.class, 5)
      .tag(String.class, "hello")
      .build();
    Call call = client.newCall(request);

    assertEquals(5, call.tag(Integer.class));
    assertEquals("hello", call.tag(String.class));
    assertEquals(null, call.tag(Boolean.class));
    assertEquals(null, call.tag(Object.class));
  }

  @Test
  public void tagsCanBeComputed() {
    Request request = new Request.Builder()

        .build();

    final long startNanos = System.nanoTime();
    final Call call = client.newCall(request);

    // Schedule a job to cancel the call in 1 second.
    executor.schedule(() -> {
      System.out.printf("%.2f Canceling call.%n", (System.nanoTime() - startNanos) / 1e9f);
      call.cancel();
      System.out.printf("%.2f Canceled call.%n", (System.nanoTime() - startNanos) / 1e9f);
    }, 1, TimeUnit.SECONDS);