"use strict";
            let port = null;
            let ackUpdated = false;
            onmessage = (ev) => {
                if (ev.data === "start") {
                    port = ev.ports[0];
                    port.onmessage = (ev) => {
                        console.log(ev.data);
                        ackUpdated = true;
                    };
                    setInterval(()=>{ 
                        if (ackUpdated) {
                            ackUpdated = false;
                        }else{
                            postMessage("cb");
                        }
                    },1500)
                }
            }