response_wrapper.go
func (w *ResponseWrapper) CloseNotify() <-chan bool {
	if notifier, ok := w.writer.(http.CloseNotifier); ok {
		c := notifier.CloseNotify()
		return c
	}

	return make(chan bool)
}
func (w *ResponseWrapper) CloseNotify() <-chan bool {
	if notifier, ok := w.writer.(http.CloseNotifier); ok {
		c := notifier.CloseNotify()
		return c
	}

	return make(chan bool)
}
// CloseNotify tries to use the original http.ResponseWriter for close
// notification. If the original writer doesn't implement http.CloseNotifier,
// it returns a channel that will never close.