code: func viewByTimeUnit(t time.Time, unit rune) string {
  	switch unit {
  	case 'Y':
  		return t.Format("2006")
  	case 'M':
  		return t.Format("200601")
  	case 'D':
  		return t.Format("20060102")
  	case 'H':
  		return t.Format("2006010215")
  	default:
  		return ""
  	}
  }
docs: // viewByTimeUnit returns the view name for time with a given quantum unit.