withLock {
      this.requestBodyOpen = true
      this.responseBodyOpen = true
    }

    if (canceled) throw IOException("Canceled")
    return result
  }

  fun acquireConnectionNoEvents(connection: RealConnection) {
    connection.assertLockHeld()

    check(this.connection == null)
    this.connection = connection
    connection.calls.add(CallReference(this, callStackTrace))
  }