arguments.go
func (w ArgWriteHelper) WriteJSON(data interface{}) error {
	return w.write(func() error {
		e := json.NewEncoder(w.writer)
		return e.Encode(data)
	})
}
func (w ArgWriteHelper) WriteJSON(data interface{}) error {
	return w.write(func() error {
		e := json.NewEncoder(w.writer)
		return e.Encode(data)
	})
}
// WriteJSON writes the given object as JSON.