IEnumerable<T> (or List<T>, or T[]) to IEnumerable (non-generic, ie. no type param)?

Hello,
I'm working on some code that takes an

object

object

that may be either an object

itself, or some form of an

IEnumerable<T>

IEnumerable<T>

. The thing is, I don't actually know

in this context (as it's a asp.net

IActionFilter

IActionFilter

). How would I check if that object is an

IEnumerable

IEnumerable

and if it is, get the object as that

IEnumerable

IEnumerable

to iterate over it?