long callId = nextCallId.getAndIncrement();
      System.out.printf("%04d %s%n", callId, call.request().url());
      return new PrintingEventListener(callId, System.nanoTime());
    }
  };

  final long callId;
  final long callStartNanos;

  public PrintingEventListener(long callId, long callStartNanos) {
    this.callId = callId;
    this.callStartNanos = callStartNanos;
  }

import kotlin.test.assertFailsWith
import mockwebserver3.MockResponse
import mockwebserver3.MockWebServer
import mockwebserver3.SocketEffect.CloseSocket
import mockwebserver3.junit5.StartStop
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

01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyEnd: byteCount=128
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] connectionReleased
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] callEnd
01-01 12:53:32.816 10999 11090 D OkHttp  : [54 ms] responseHeadersStart

01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] responseBodyEnd: byteCount=128
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] connectionReleased
01-01 12:53:32.811 10999 11089 D OkHttp  : [49 ms] callEnd
01-01 12:53:32.816 10999 11090 D OkHttp  : [54 ms] responseHeadersStart

    call: Call,
    ioe: IOException,
  ) {
    logWithTime("responseFailed: $ioe")

    delegate.responseFailed(call, ioe)
  }

  override fun callEnd(call: Call) {
    logWithTime("callEnd")

    delegate.callEnd(call)
  }

  override fun callFailed(
    call: Call,
    ioe: IOException,
  ) {
    logWithTime("callFailed: $ioe")

    delegate.callFailed(call, ioe)

document's age at the time it was served based on "Last-Modified". Default expiration dates aren't used for URIs 
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.

        long callId = nextCallId.getAndIncrement();
        System.out.printf("%04d %s%n", callId, call.request().url());
        return new PrintingEventListener(callId, System.nanoTime());
      }
    };

    final long callId;
    final long callStartNanos;

    PrintingEventListener(long callId, long callStartNanos) {
      this.callId = callId;
      this.callStartNanos = callStartNanos;
    }

 * `dnsStart(call, domainName)` → `dnsEnd(call, domainName, inetAddressList)`.
 *
 * Events are typically nested with this structure:
 *
 *  * call ([callStart], [callEnd], [callFailed])
 *    * proxy selection ([proxySelectStart], [proxySelectEnd])
 *    * dns ([dnsStart], [dnsEnd])
 *    * connect ([connectStart], [connectEnd], [connectFailed])

  }

  override fun responseFailed(
    call: Call,
    ioe: IOException,
  ) {
    logWithTime("responseFailed: $ioe")
  }

  override fun callEnd(call: Call) {
    logWithTime("callEnd")
  }

  override fun callFailed(
    call: Call,
    ioe: IOException,
  ) {
    logWithTime("callFailed: $ioe")
  }

  override fun canceled(call: Call) {

      .assertLogMatch(Regex("""responseBodyStart"""))
      .assertLogMatch(Regex("""responseBodyEnd: byteCount=6"""))
      .assertLogMatch(Regex("""connectionReleased"""))
      .assertLogMatch(Regex("""callEnd"""))
      .assertNoMoreLogs()
  }

  @Test
  fun post() {
    assumeNotWindows()
    server.enqueue(MockResponse())
    client.newCall(request().post("Hello!".toRequestBody(PLAIN)).build()).execute()