code: func HumanDuration(d time.Duration) string {
  	// Allow deviation no more than 2 seconds(excluded) to tolerate machine time
  	// inconsistence, it can be considered as almost now.
  	if seconds := int(d.Seconds()); seconds < -1 {
  		return fmt.Sprintf("<invalid>")
  	} else if seconds < 0 {
  		return fmt.Sprintf("0s")
  	} else if seconds < 60*2 {
  		return fmt.Sprintf("%ds", seconds)
  	}
  	minutes := int(d / time.Minute)
  	if minutes < 10 {
  		s := int(d/time.Second) % 60
  		if s == 0 {
  			return fmt.Sprintf("%dm", minutes)
  		}
  		return fmt.Sprintf("%dm%ds", minutes, s)
  	} else if minutes < 60*3 {
  		return fmt.Sprintf("%dm", minutes)
  	}
  	hours := int(d / time.Hour)
  	if hours < 8 {
  		m := int(d/time.Minute) % 60
  		if m == 0 {
  			return fmt.Sprintf("%dh", hours)
  		}
  		return fmt.Sprintf("%dh%dm", hours, m)
  	} else if hours < 48 {
  		return fmt.Sprintf("%dh", hours)
  	} else if hours < 24*8 {
  		h := hours % 24
  		if h == 0 {
  			return fmt.Sprintf("%dd", hours/24)
  		}
  		return fmt.Sprintf("%dd%dh", hours/24, h)
  	} else if hours < 24*365*2 {
  		return fmt.Sprintf("%dd", hours/24)
  	} else if hours < 24*365*8 {
  		return fmt.Sprintf("%dy%dd", hours/24/365, (hours/24)%365)
  	}
  	return fmt.Sprintf("%dy", int(hours/24/365))
  }
docs: // HumanDuration returns a succint representation of the provided duration
  // with limited precision for consumption by humans. It provides ~2-3 significant
  // figures of duration.