Casting error on RecyclerView

[haskellcamargo]

Well, it may be a trivial error, but, whenever I try to cast a RecyclerView to a ObservableRecyclerView, I get an error, right on the first line. I'm following the example on this link.

Is it any incompatibility of this specific version of RecyclerView? The error happens just on

final ObservableRecyclerView recyclerView = (ObservableRecyclerView) view.findViewById(R.id.recyclerview);