code: func (h Handler) serveHTTPForOp(w http.ResponseWriter, r *http.Request, op Operation) {
  	if Allowed(r, op) {
  		h.Handler.ServeHTTP(w, r)
  	} else {
  		SendUnauthorized(w, r)
  	}
  }
docs: // serveHTTPForOp serves only if op is allowed for this request and auth mode.