In Commodity Futures Trading Commission v. Schor, 478 U.S. 833, 106 S.Ct. 3245, 92 L.Ed.2d 675 (1986), the Court endorsed a case-by-case, functional inquiry into Article III challenges: Among the factors upon which we have focused are the extent to which the "essential attributes of judicial power" are reserved to Article III courts, and conversely, the extent to which the non-Article III forum exercises the range of jurisdiction and powers normally vested only in Article III courts, the origins and importance of the right to be adjudicated, and the concerns that drove Congress to depart from the requirements of Article III. Id. at 851, 106 S.Ct. 3245. No one factor predominates. Id.