code: func (c Calendar) formatDateTime(datetime time.Time, pattern []*datetimePatternComponent) (string, error) {
  	formatted := ""
  	for _, component := range pattern {
  		if component.componentType == datetimePatternComponentLiteral {
  			formatted += component.pattern
  		} else {
  			f, err := c.formatDateTimeComponent(datetime, component.pattern)
  			if err != nil {
  				return "", err
  			}
  			formatted += f
  		}
  	}
  
  	return strings.Trim(formatted, " ,"), nil
  }
docs: // formatDateTime takes a time.Time and a sequence of parsed pattern components
  // and returns an internationalized string representation.