     ///
     /// // 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

    ///   - respond: respond: `(request: Request, next: Responder) throws -> Future<Response>`
    ///   - configure: Group configuration function
    ///
    public func using(_ respond: @escaping MiddlewareFunction.Respond, configure: (RouteGroup) -> ()) {
        configure(RouteGroup(cascadingTo: self, middleware: [MiddlewareFunction(respond)]))
    }
}

    /// let userMustBeAuthorized = AuthorizationMiddleware()
    ///
    /// // creating new group on router
    /// router.group(using: AuthorizationMiddleware) { group in
    ///
    ///         // adding "user/profile/" route to router
    ///         // AuthorizationMiddleware is applied
