     ///
     /// // creating new group on router
     /// let users = router.group("user")
-    ///     .using(userMustBeAuthorized)
-    ///     .using(userMustBeCurrentUser)
+    ///     .grouped(using: userMustBeAuthorized)
+    ///     .grouped(using: userMustBeCurrentUser)
     ///
     /// // adding "user/profile/" route to router
     /// // both of validations applied

    ///
    /// - Parameter middleware: Middleware
    /// - Returns: RouterGroup with middleware attached
    public func using(_ middleware: Middleware...) -> RouteGroup {
        return RouteGroup(cascadingTo: self, middleware: middleware)
    }
    

    /// - Parameter respond: `(request: Request, next: Responder) throws -> Future<Response>`
    ///
    /// - Returns: RouterGroup with closure attached
    public func grouped(using respond: @escaping MiddlewareFunction.Respond) -> RouteGroup {
        return RouteGroup(cascadingTo: self, middleware: [MiddlewareFunction(respond)])
    }
    
