What is the test for res judicata?

The traditional doctrine of res judicata is that a valid final judgment on the merits operates to bind the parties both as to issues actually litigated and determined in the first action and as to those issues which might have been, but were not, actually raised and decided in that first action. Saylor v. Lindsley, 391 F.2d 965, 968 (2d Cir. 1968).