route(request: dever.http.Request, reply: dever.system.HttpReply) () {
  selected(request.target == "/sse", reply)
}

selected(sse: true, reply: dever.system.HttpReply) () {
  dever.sse.start(reply, [])
  dever.sse.send(reply, dever.sse.Event { event = "change", data = "一\n二", id = "", retry_ms = 10 })
  dever.task.sleep(250)
  dever.http.finish(reply)
}
selected(sse: false, reply: dever.system.HttpReply) () {
  dever.http.start(reply, 200, [])
  dever.http.write(reply, dever.bytes.fromText("first"))
  dever.task.sleep(250)
  dever.http.write(reply, dever.bytes.fromText("last"))
}

serve() () {
  listener = dever.net.listen("127.0.0.1", 0)
  port = dever.net.port(listener)
  blocking(dever.io.println(int.toText(port)))
  limits = dever.http.defaultLimits()
  limits.timeout_ms = 100
  live = dever.http.defaultLiveLimits()
  live.heartbeat_ms = 30
  live.idle_ms = 500
  dever.http.serveLive(route, listener, limits, live)
}