function main() {
    var APIKEY = "your Access Key(Bitmex API ID)"
    var expires = parseInt(Date.now() / 1000) + 10
    var signature = exchange.HMAC("sha256", "hex", "GET/realtime" + expires, "{{secretkey}}")//secretkey在执行时自动替换，不用填写
    var client = Dial("wss://www.bitmex.com/realtime", 60)
    var auth = JSON.stringify({args: [APIKEY, expires, signature], op: "authKeyExpires"})
    var pos = 0
    client.write(auth)