fetch/fetch.go
func (p FulfillRequestParams) WithResponsePhrase(responsePhrase string) *FulfillRequestParams {
	p.ResponsePhrase = responsePhrase
	return &p
}
func (p FulfillRequestParams) WithResponsePhrase(responsePhrase string) *FulfillRequestParams {
	p.ResponsePhrase = responsePhrase
	return &p
}
// WithResponsePhrase a textual representation of responseCode. If absent, a
// standard phrase mathcing responseCode is used.