code: func (h *ResponseHeaders) Set(value string) error {
  	splitResult := strings.SplitN(value, "=", 2)
  
  	if len(splitResult) != 2 {
  		return errors.New("header flag must be in name=value format")
  	}
  
  	*h = append(*h, Header{Name: splitResult[0], Value: splitResult[1]})
  	return nil
  }
docs: // Set method appends new Header object from header=value notation