Angular: Countdown

<strong>let</strong> countDownValue = 5;

<strong>let</strong> countDownTimerSubs = timer(0, 1000)
  .pipe(
    take(countDownValue),
    map(() => --countDownValue)
  )
  .subscribe(val => {
    countDownValue = val;
    <strong>this</strong>.insignia_content = val.toString();
  });