The ornamental design for a case, as shown and described.
FIG. 1 is a perspective view of a case showing my new design;
FIG. 2 is a top plan view thereof; and,
FIG. 3 is a front elevation view thereof.
The broken line showing of a case in FIGS. 1–3 is included for the purpose of illustrating environmental portions of the case and forms no part of the claimed design.