exchangeIndex = 0,
          socket = MockWebServerSocket(socket),
        )
        socket.close()
      } else {
        openClientSockets.add(socket)
        serveConnection(nextConnectionIndex++, socket, peek)
      }
    }
  }

  public override fun close() {
    if (closed) return
    closed = true

    if (!started) return // Nothing to shut down.