override fun execute(): Response = error("unexpected")

  override fun enqueue(responseCallback: Callback): Unit = error("unexpected")

  override fun cancel(): Unit = error("unexpected")

  override fun isExecuted(): Boolean = error("unexpected")

  override fun isCanceled(): Boolean = error("unexpected")

  override fun timeout(): Timeout = error("unexpected")

  fun cancel()

  /**
   * Returns true if this call has been either [executed][execute] or [enqueued][enqueue]. It is an
   * error to execute a call more than once.
   */
  fun isExecuted(): Boolean

  fun isCanceled(): Boolean

  /**
   * Returns a timeout that spans the entire call: resolving DNS, connecting, writing the request