code: func SetTimerPrecision(precision time.Duration) {
  	if precision < time.Millisecond {
  		panic("time precision can not less than a Millisecond")
  	}
  	timer.Precision = precision
  }
docs: // SetTimerPrecision set the ticker precision, and time precision can not less
  // than a Millisecond, and can not change after application running. The default
  // precision is time.Second