rest/recorder.go
func (w *recorderResponseWriter) WriteJson(v interface{}) error {
	b, err := w.EncodeJson(v)
	if err != nil {
		return err
	}
	_, err = w.Write(b)
	if err != nil {
		return err
	}
	return nil
}
func (w *recorderResponseWriter) WriteJson(v interface{}) error {
	b, err := w.EncodeJson(v)
	if err != nil {
		return err
	}
	_, err = w.Write(b)
	if err != nil {
		return err
	}
	return nil
}
// Make sure the local Write is called.