Gotcha. I do see that they're indeed used, but I wouldn't be totally opposed to redefining the same method signatures for the id and original url in the new interface (i.e. `SingleLogoutService`, etc) We are kind of doing the same thing with `Ticket` and `TicketState` interfaces anyway, so it would be somewhat consistent with the current practice. 

Ideally, I'd really want to do away with duplicate code but it seems like sometimes and for the time being, it would make sense. 

What do you think?