The ornamental design for stacked cases, as shown and described.
FIG. 1 is a perspective view of stacked cases showing the new ornamental design, the portions shown in broken lines forming no part of the design sought to be patented;
FIG. 2 is a top view thereof, the portions shown in broken lines forming no part of the design sought to be patented;
FIG. 3 is a front view thereof, the portions shown in broken lines forming no part of the design sought to be patented;
FIG. 4 is a bottom view thereof, and the portions shown in broken lines forming no part of the design sought to be patented;
FIG. 5 is a back view thereof, and the portions shown in broken lines forming no part of the design sought to be patented; and,
FIG. 6 is a left side view thereof, the left and right views being a mirror image, and the portions shown in broken lines forming no part of the design sought to be patented.