How to return user name from vibed session?

[Adrian Matoga via Digitalmars-d-learn]

On Thursday, 10 December 2015 at 11:36:20 UTC, Suliman wrote:
> Vibed have method get for user session 
> http://vibed.org/api/vibe.http.session/SessionStore
>
> I set user name for session like this:
> req.session.set("username", "admin");
>
> But I can't understand how to get user name from it:
>
> abstract std.variant.VariantN!(20) get(
>   string id,
>   string name,
>   lazy std.variant.VariantN!(20) defaultVal
> );
>
> What does every string here mean? Could anybody to show example 
> of usage?

I think what you need is Session.get, not SessionStore.get:

http://vibed.org/api/vibe.http.session/Session.get