code: func (dt *DateTimeRFC2616) UnmarshalJSON(b []byte) error {
  	ts, err := time.Parse(dateTimeRFC2616FmtTicked, string(b))
  	if err != nil {
  		return err
  	}
  
  	*dt = DateTimeRFC2616(ts)
  	return nil
  }
docs: // UnmarshalJSON override unmarshalJSON