## Version 4.3.0

_2019-12-31_

 *  Fix: Degrade HTTP/2 connections after a timeout. When an HTTP/2 stream times out it may impact
    the stream only or the entire connection. With this fix OkHttp will now send HTTP/2 pings after
    a stream timeout to determine whether the connection should remain eligible for pooling.

 *  Fix: Don't call `EventListener.responseHeadersStart()` or `responseBodyStart()` until bytes have

    assertThat(server.receivedPongCount()).isEqualTo(0)
    closeWebSockets(webSocket, server)
  }

  /**
   * Configure the websocket to send pings every 500 ms. Artificially prevent the server from
   * responding to pings. The client should give up when attempting to send its 2nd ping, at about
   * 1000 ms.
   */
  @Test
  fun unacknowledgedPingFailsConnection() {
    assumeNotWindows()

    client.processNextFrame()
    taskFaker.runTasks()
    server.webSocket!!.pong("pong 3".encodeUtf8())
    client.processNextFrame()

    // After 500ms the client automatically pings and the server pongs back.
    taskFaker.advanceUntil(ns(500L))
    server.processNextFrame() // Ping.
    client.processNextFrame() // Pong.

        .pingInterval(Duration.ofMillis(500))
        .build()

    // Set up the server to ignore the socket. It won't respond to pings!
    server.enqueue(MockResponse(socketPolicy = StallSocketAtStart))

    // Make a call. It'll fail as soon as our pings detect a problem.
    val call = client.newCall(Request(server.url("/")))
    val executeAtNanos = System.nanoTime()

  /** True if this web socket failed and the listener has been notified. */
  private var failed = false

  /** Total number of pings sent by this web socket. */
  private var sentPingCount = 0

  /** Total number of pings received by this web socket. */
  private var receivedPingCount = 0

  /** Total number of pongs received by this web socket. */
  private var receivedPongCount = 0

     *
     * The default value of 0 disables client-initiated pings.
     */
    fun pingInterval(
      interval: Long,
      unit: TimeUnit,
    ) = apply {
      pingInterval = checkDuration("interval", interval, unit)
    }

    /**
     * Sets the interval between HTTP/2 and web socket pings initiated by this client. Use this to

  private val settingsListenerQueue = taskRunner.newQueue()

  /** User code to run in response to push promise events. */
  private val pushObserver: PushObserver = builder.pushObserver

  // Total number of pings send and received of the corresponding types. All guarded by this.
  private var intervalPingsSent = 0L
  private var intervalPongsReceived = 0L
  private var degradedPingsSent = 0L
  private var degradedPongsReceived = 0L

## Version 5.0.0-alpha.2

_2021-01-30_

**In this release MockWebServer has a new Maven coordinate and package name.** A longstanding
problem with MockWebServer has been its API dependency on JUnit 4. We've reorganized things to
remove that dependency while preserving backwards compatibility.

| Maven Coordinate                                         | Package Name          | Description                       |

      .build()
    assertThat(original.interceptors.size).isEqualTo(0)
    assertThat(original.networkInterceptors.size).isEqualTo(0)
  }

  /**
   * When copying the client, stateful things like the connection pool are shared across all
   * clients.
   */
  @Test fun cloneSharesStatefulInstances() {
    val client = clientTestRule.newClient()

    // Values should be non-null.