Isn't there "Filters" in CI?

[eluser]Skyblaze[/eluser]
I see that there isn't "Filters" (special functions that are executed at specific times before every method/function in the controller) in CI. If i have to put some code that tests if an user is authenticated (watching the session) for all the methods/pages in the controller i know that i can put that code in the controller constructor but that is limited. Like so i can only run that code for all the methods in the controller but what if i want it executes only for ceratin methods? Then in the constructor i can put only one type of code.....if i have to run also another piece of code for all the methods?