In 2015, when the U.S. Supreme Court ruled that a final judgment in one but not all the cases consolidated under the multidistrict-litigation statute (28 U. S. C. Section 1407) is immediately appealable, Gelboim v. Bank of America, 135 S. Ct. 897, the high court left open the question of whether the answer would be the same for cases consolidated under Federal Rule of Civil Procedure 42(a) — but a fierce feud between two siblings gave the Supreme Court an opportunity to answer that question.The separate suits that …