Go의 net/http 패키지에서 HTTP 핸들러를 어떻게 동적으로 등록하고 등록 취소할 수 있나요?

<code class="go">type HandlerFactory struct {
    handler_id int
}

func (hf *HandlerFactory) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    hf.handler_id++
    handler := MyHandler{hf.handler_id}
    handle := fmt.Sprintf("/%d/", hf.handler_id)
    http.Handle(handle, &handler)
}</code>

<code class="go">type MyMux struct {
    http.ServeMux
    mu sync.Mutex
}

func (mux *MyMux) Deregister(pattern string) error {
    mux.mu.Lock()
    defer mux.mu.Unlock()
    del(mux.m, pattern)

    // Handle additional error checking or setup here
}</code>

<code class="go">mux := new(MyMux)
mux.Handle("/create", &factory)

srv := &http.Server{
    Addr:    "localhost:8080",
    Handler: mux,
}

go srv.ListenAndServe()

// Deregister handlers as needed
mux.Deregister("/123/*")</code>