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import { serve } from "https://deno.land/std@0.143.0/http/mod.ts";
const port = 8089;serve(handleReq, { port });console.log("Ready");
function handleReq(req: Request): Response {  const upgrade = req.headers.get("upgrade") || "";  if (upgrade.toLowerCase() !== "websocket") {    return new Response("request isn't trying to upgrade to websocket.");  }  const { socket, response } = Deno.upgradeWebSocket(req);  let value = 0;  socket.onmessage = (e) => {    console.error("socket message:", e.data);    value++;    socket.send(value.toString());  };  socket.onerror = (e) => {    console.error("Had error:", (e as any).message);  };  return response;}