![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(

    cancelLatch.await()

    val events = listener.eventSequence.filter { isConnectionEvent(it) }.map { it.name }
    listener.clearAllEvents()

    assertThat(events).startsWith("CallStart", "ConnectStart", "ConnectEnd", "ConnectionAcquired")
    if (cancelMode == CANCEL) {
      assertThat(events).contains("Canceled")
    } else {
      assertThat(events).doesNotContain("Canceled")
    }

    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?) {