abcd.callStart(FailingCall())

    assertThat(a.takeEvent()).isInstanceOf<CallStart>()
    assertThat(a.eventSequence).isEmpty()
    assertThat(b.takeEvent()).isInstanceOf<CallStart>()
    assertThat(b.eventSequence).isEmpty()
    assertThat(c.takeEvent()).isInstanceOf<CallStart>()
    assertThat(c.eventSequence).isEmpty()

   *
   * This will be invoked only once for a single [Call]. Retries of different routes or redirects
   * will be handled within the boundaries of a single [callStart] and [callEnd]/[callFailed] pair.
   */
  open fun callStart(call: Call) {
  }

  /**
   * Invoked for calls that were not executed immediately because resources weren't available. The
   * call will remain in the queue until resources are available.

  override fun connectionReleased(
    call: Call,
    connection: Connection,
  ) = onEvent(ConnectionReleased(System.nanoTime(), call, connection))

  override fun callStart(call: Call) = onEvent(CallStart(System.nanoTime(), call))

  override fun requestHeadersStart(call: Call) =
    onEvent(
      RequestHeadersStart(
        System.nanoTime(),
        call,
      ),
    )

import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.junit5.StartStop
import okhttp3.CallEvent.CallEnd
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.ConnectEnd
import okhttp3.CallEvent.ConnectStart
import okhttp3.CallEvent.ConnectionAcquired
import okhttp3.CallEvent.ConnectionReleased
import okhttp3.CallEvent.DnsEnd

    dispatcher.maxRequests = 2 // Trigger promotion.
    callback.await(request2.url).assertFailure(InterruptedIOException::class.java)
    assertThat(eventRecorder.recordedEventTypes())
      .containsExactly(CallStart::class, CallStart::class, CallFailed::class)
  }

  @Test
  fun executionRejectedAfterMaxRequestsPerHostChange() {
    val request1 = newRequest("http://a/1")
    val request2 = newRequest("http://a/2")

    timeout.enter()
    callStart()
    try {
      client.dispatcher.executed(this)
      return getResponseWithInterceptorChain()
    } finally {
      client.dispatcher.finished(this)
    }
  }

  override fun enqueue(responseCallback: Callback) {
    check(executed.compareAndSet(false, true)) { "Already Executed" }

    callStart()

import assertk.assertions.isInstanceOf
import assertk.assertions.matchesPredicate
import java.util.Deque
import java.util.concurrent.ConcurrentLinkedDeque
import java.util.concurrent.TimeUnit
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.Canceled
import org.junit.jupiter.api.Assertions.fail

open class EventRecorder(
  /**
   * An override to ignore the normal order that is enforced.

 */
class LoggingEventListener private constructor(
  private val logger: HttpLoggingInterceptor.Logger,
) : EventListener() {
  private var startNs: Long = 0

  override fun callStart(call: Call) {
    startNs = System.nanoTime()

    logWithTime("callStart: ${call.request()}")
  }

  override fun dispatcherQueueStart(
    call: Call,
    dispatcher: Dispatcher,
  ) {

    }

    // Observed Events are variable
    // JDK 14
    // CallStart, ProxySelectStart, ProxySelectEnd, DnsStart, DnsEnd, ConnectStart, SecureConnectStart,
    // SecureConnectEnd, ConnectEnd, ConnectionAcquired, RequestHeadersStart, RequestHeadersEnd,
    // ResponseFailed, ConnectionReleased, CallFailed
    // JDK 8
    // CallStart, ProxySelectStart, ProxySelectEnd, DnsStart, DnsEnd, ConnectStart, SecureConnectStart,

  }

  data class CallStart(
    override val timestampNs: Long,
    override val call: Call,
  ) : CallEvent()

  data class CallEnd(
    override val timestampNs: Long,
    override val call: Call,
  ) : CallEvent() {
    override fun closes(event: CallEvent): Boolean = event is CallStart && call == event.call
  }

  data class CallFailed(