Hopefully this is a simple one, but I have some custom middleware which I want to return a 404 or 401 etc to the user and stop the propagation of other handlers etc.

I was expecting I could do something like:

```
function SomeMiddleware(req, res, next) {
   if(user.notRealOrSomething)
   { throw new HttpException(401, "Tough luck buddy"); }

   return next();
}

```

However cannot find any specific info about how is best to do this.