mutableListOf<String>().apply {
        add("CallStart")
        if (connectionType != H2) {
          addAll(listOf("ConnectStart", "ConnectEnd"))
        }
        addAll(listOf("ConnectionAcquired", "ConnectionReleased", "CallEnd"))
      }

    assertThat(events2).isEqualTo(expectedEvents2)
  }

  private fun isConnectionEvent(it: CallEvent?) =
    it is CallStart ||
      it is CallEnd ||

    long nowNanos = System.nanoTime();
    if (name.equals("callStart")) {
      callStartNanos = nowNanos;
    }
    long elapsedNanos = nowNanos - callStartNanos;
    System.out.printf("%.3f %s%n", elapsedNanos / 1000000000d, name);
  }

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

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

  }

  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(

   *
   * 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 prior to a proxy selection.
   *
   * This will be invoked for route selection regardless of whether the client

  EventListener.Factory {
  private var startNs: Long? = null

  override fun create(call: Call): EventListener = this

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

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

    delegate.callStart(call)
  }

  override fun proxySelectStart(
    call: Call,
    url: HttpUrl,
  ) {
    logWithTime("proxySelectStart: $url")

    }

    // 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,

containing a query.

 - CallStart
 - **CacheHit**
 - CallEnd
 
### Cache Miss

Under a cache miss the normal request events are seen but an additional event shows the presence of the cache.
Cache Miss will be typical if the item has not been read from the network, is uncacheable, or is past it's 
lifetime based on Response cache headers.

 - CallStart 
 - **CacheMiss**
 - ProxySelectStart

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

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

import mockwebserver3.SocketPolicy.DisconnectDuringResponseBody
import mockwebserver3.SocketPolicy.FailHandshake
import okhttp3.CallEvent.CallEnd
import okhttp3.CallEvent.CallFailed
import okhttp3.CallEvent.CallStart
import okhttp3.CallEvent.ConnectStart
import okhttp3.CallEvent.ConnectionAcquired
import okhttp3.CallEvent.DnsEnd
import okhttp3.CallEvent.DnsStart
import okhttp3.CallEvent.RequestBodyEnd

    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()