Near the end of Elena Langer’s new opera Figaro Gets a Divorce, as the Almaviva household — now emigrés in an unnamed 1930s police state — prepares to flee, the Countess announces that she intends to leave her trunk behind. It’s not the subtlest moment in David Pountney’s libretto. Any opera that sets itself up as a sequel to The Marriage of Figaro is already courting comparisons that are both completely unavoidable and massively unfair.