Fix #4373 : add comment

Signed-off-by: Cabinfever_B <cabinfeveroier@gmail.com>

pkg/apiutil/serverapi/middleware.go

@@ -79,6 +79,22 @@ func IsServiceAllowed(s *server.Server, group server.ServiceGroup) bool {
 	return false
 }
 
+type selfProtector struct {
+	s *server.Server
+}
+
+func NewSelfProtector(s *server.Server) negroni.Handler {
+	return &selfProtector{s: s}
+}
+
+func (protector *selfProtector) ServeHTTP(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
+	if protector.s.SelfProtectionHandler.SelfProtectionHandleHTTP(r) {
+		next(w, r)
+	} else {
+		http.Error(w, http.StatusText(http.StatusTooManyRequests), http.StatusTooManyRequests)
+	}
+}
+
 type redirector struct {
 	s *server.Server
 }