What is the test for having evidence of "other crimes, wrongs or acts" under Rule 404(b)?

offense,'" is not evidence of "other crimes, wrongs, or acts" under Rule 404(b). United States v. Quinones, 511 F.3d 289, 309 (2d Cir. 2007) (quoting United States v. Towne, 870 F.2d 880, 886 (2d Cir. 1989)). Rather, if it "'complete[s] the story of the crime on trial,'" id. (quoting Towne, 870 F.2d at 886), then the evidence of the uncharged act is properly "treated as 'part of the very act charged,' or, at least, as proof of that act," id. (quoting United States v. Concepcion, 983 F.2d 369, 392 (2d Cir. 1992)).