mux.go
func methodNotAllowedHandler(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(405)
	w.Write(nil)
}
func methodNotAllowedHandler(w http.ResponseWriter, r *http.Request) {
	w.WriteHeader(405)
	w.Write(nil)
}
func methodNotAllowedHandler ( w http . ResponseWriter , r * http . Request ) { w . WriteHeader ( 405 ) w . Write ( nil ) }
// methodNotAllowedHandler is a helper function to respond with a 405,
// method not allowed.
methodNotAllowedHandler is a helper function to respond with a 405 method not allowed .