When the client cannot unmarshal an error response, the response is lost

[taylor-sutton]

Example generated code:

wag/samples/gen-go/client/client.go

Lines 327 to 330 in e1e9b5b

	var output models.BadRequest
	if err := json.NewDecoder(resp.Body).Decode(&output); err != nil {
	return nil, "", err
	}

This is is perhaps a bit tricky to handle better if we want to continue with allowing the response body to be streamed?