Method setTimeout

src/tests/backend/specs/SecretRotator.ts:77–83

(fn:Function, wait = 0)

  get now() { return this._now; }
  setTimeout(fn:Function, wait = 0) {
    const when = this._now + wait;
    const id = this._nextId++;
    this.timeouts.set(id, {id, fn, when});
    this._fire();
    return id;
  }
  clearTimeout(id:number) { this.timeouts.delete(id); }
}