![Events Diagram](../assets/images/events@2x.png)

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java

events@2x.png...

events******@****.***...

events******@****.***...

      throw AssertionError("full event sequence: $fullEventSequence", e)
    }
  }

  /**
   * Remove and return the next event from the recorded sequence.
   *
   * @param eventClass a class to assert that the returned event is an instance of, or null to
   *     take any event class.
   * @param elapsedMs the time in milliseconds elapsed since the immediately-preceding event, or
   *     -1L to take any duration.
   */

  }

  fun assertExhausted() {
    assertThat(events).isEmpty()
  }

  fun assertOpen(): WebSocket {
    val event = nextEvent() as Open
    return event.webSocket
  }

  fun assertFailure(t: Throwable?) {
    val event = nextEvent() as Failure
    assertThat(event.response).isNull()
    assertThat(event.t).isSameAs(t)
  }

  fun assertFailure(

    been received. Previously these events were incorrectly sent too early, when OkHttp was ready to
    read the response headers or body, which mislead tracing tools. Note that the `responseFailed()`
    event always used to follow one of these events; now it may be sent without them.

 *  New: Upgrade to Kotlin 1.3.61.

  }

  @Test
  fun idCleared() {
    consumeEvents(
      """
      |data: first event
      |id: 1
      |
      |data: second event
      |id
      |
      |data: third event
      |
      |
      """.trimMargin(),
    )
    assertThat(callbacks.remove()).isEqualTo(Event("1", null, "first event"))

  }

  fun assertEvent(
    id: String?,
    type: String?,
    data: String,
  ) {
    assertThat(nextEvent()).isEqualTo(Event(id, type, data))
  }

  fun assertOpen(): EventSource {
    val event = nextEvent() as Open
    return event.eventSource
  }

  fun assertClose() {
    nextEvent() as Closed
  }

  fun assertFailure(message: String?) {

          maxSize = 50L * 1024L * 1024L // 50 MiB
      ))
      .build()
```

## EventListener events 

Cache Events are exposed via the EventListener API.  Typical scenarios are below.

### Cache Hit

In the ideal scenario the cache can fulfill the request without any conditional call to the network.
This will skip the normal events such as DNS, connecting to the network, and downloading the response body.