Adds panic when using too many handlers

routergroup.go

@@ -148,6 +148,9 @@ func (group *RouterGroup) createStaticHandler(relativePath string, fs http.FileS
 
 func (group *RouterGroup) combineHandlers(handlers HandlersChain) HandlersChain {
 	finalSize := len(group.Handlers) + len(handlers)
+	if finalSize >= AbortIndex {
+		panic("too many handlers")
+	}
 	mergedHandlers := make(HandlersChain, finalSize)
 	copy(mergedHandlers, group.Handlers)
 	copy(mergedHandlers[len(group.Handlers):], handlers)