What is the test for a motion of no confidence in a jury in a civil case?

As an initial matter, we must bear in mind the injunction of Arizona v. Washington, 434 U.S. 497, 98 S.Ct. 824, 54 L.Ed.2d 717 (1978), that a trial judge's determination or perceptions must be given "great deference," id. at 510, 98 S.Ct. at 832, and that "necessity" is not to be taken literally, id. at 511, 98 S.Ct. at 833 ("In a strict, literal sense, the mistrial was not 'necessary.' "). Our duty is to be sure that the trial judge exercised " 'sound discretion' in declaring a mistrial." Id. at 514, 98 S.Ct. at 834, accord United States v. Grasso, 600 F.2d 342, 344 & n.6 (2d Cir.1979).