Appeal from an interlocutory order. Interlocutory appeals are extremely rare; a three-part test determines whether the collateral order exception to res judicata makes such an appeal possible:
- the order must have conclusively determined the disputed question;
- the order must “resolve an issue completely separate from the merits of the action”;
- the order must be “effectively unreviewable on appeal from a final judgment.”
(Hallock v. Bonner, 387 F.3d 147 (2d Cir. 2004).)