override val connection: Connection,
    val call: Call,
  ) : ConnectionEvent()

  data class ConnectionReleased(
    override val timestampNs: Long,
    override val connection: Connection,
    val call: Call,
  ) : ConnectionEvent() {
    override fun closes(event: ConnectionEvent): Boolean =
      event is ConnectionAcquired && connection == event.connection && call == event.call
  }

    connection: Connection,
    route: Route,
    call: Call,
  ) {}

  /**
   * Invoked when a connection is released as no longer required.
   */
  open fun connectionClosed(connection: Connection) {}

  /**
   * Invoked when a call is assigned a particular connection.
   */
  open fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {}

  /**

  )

  fun connectionConnectEnd(
    connection: Connection,
    route: Route,
  )

  fun connectFailed(
    route: Route,
    protocol: Protocol?,
    e: IOException,
  )

  fun connectionAcquired(connection: Connection)

  fun acquireConnectionNoEvents(connection: RealConnection)

  fun releaseConnectionNoEvents(): Socket?

  fun connectionReleased(connection: Connection)

  }

  /**
   * Invoked after a connection has been acquired for the `call`.
   *
   * This can be invoked more than 1 time for a single [Call]. For example, if the response
   * to the [Call.request] is a redirect to a different address.
   */
  open fun connectionAcquired(
    call: Call,
    connection: Connection,
  ) {
  }

  /**
   * Invoked after a connection has been released for the `call`.
   *

    server.bodyLimit = 7 * 512 * 1024
    val connection = server.url("/").toUrl().openConnection() as HttpURLConnection
    connection.requestMethod = "POST"
    connection.doOutput = true
    connection.setFixedLengthStreamingMode(1024 * 1024 * 1024) // 1 GB
    connection.connect()
    val out = connection.outputStream
    val data = ByteArray(1024 * 1024)
    var i = 0
    while (i < 1024) {

   * That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

    fun trackFailure(

    // which can satisfy a larger policy
    val connection = routePlanner.plans.first().connection
    val http2Connection = connectHttp2(peer, connection, 5)
    setPolicy(pool, address, ConnectionPool.AddressPolicy(5))
    assertThat(pool.connectionCount()).isEqualTo(1)

    // Decrease the connection's max so that another connection is needed

    // flow-control window is fully depleted.
    if (!flushHeaders) {
      this.withLock {
        flushHeaders = (connection.writeBytesTotal >= connection.writeBytesMaximum)
      }
    }

    connection.writeHeaders(id, outFinished, responseHeaders)

    if (flushHeaders) {
      connection.flush()
    }
  }

  )

  override fun connectEnd(
    connection: Connection,
    route: Route,
    call: Call,
  ) {
    logEvent(ConnectionEvent.ConnectEnd(System.nanoTime(), connection, route, call))
  }

  override fun connectionClosed(connection: Connection) = logEvent(ConnectionEvent.ConnectionClosed(System.nanoTime(), connection))

  override fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {

     * automatically send ping frames until either the connection fails or it is closed. This keeps
     * the connection alive and may detect connectivity failures.
     *
     * If the server does not respond to each ping with a pong within `interval`, this client will
     * assume that connectivity has been lost. When this happens on a web socket the connection is