code: func (c Calendar) formatDateTimeComponentMonth(datetime time.Time, length int) (string, error) {
  
  	month := int(datetime.Month())
  
  	switch length {
  	case datetimeFormatLength1Plus:
  		return c.formatDateTimeComponentMonth1Plus(month), nil
  	case datetimeFormatLength2Plus:
  		return c.formatDateTimeComponentMonth2Plus(month), nil
  	case datetimeFormatLengthAbbreviated:
  		return c.formatDateTimeComponentMonthAbbreviated(month), nil
  	case datetimeFormatLengthWide:
  		return c.formatDateTimeComponentMonthWide(month), nil
  	case datetimeFormatLengthNarrow:
  		return c.formatDateTimeComponentMonthNarrow(month), nil
  	}
  
  	return "", fmt.Errorf("unsupported month length: %d", length)
  }
docs: // formatDateTimeComponentMonth renders a month component.