response.go
func (w *Response) CloseNotify() <-chan bool {
	if cn, ok := w.ResponseWriter.(closeNotifier); ok {
		return cn.CloseNotify()
	}
	return nil
}
func (w *Response) CloseNotify() <-chan bool {
	if cn, ok := w.ResponseWriter.(closeNotifier); ok {
		return cn.CloseNotify()
	}
	return nil
}
// CloseNotify implements the http.CloseNotifier interface