The ornamental design for a containercover, as shown and described.
FIG. 1 is a perspective view of a container cover showing our new design;
FIG. 2 is an environmental front elevational view thereof;
FIG. 3 is a right side elevational view, with the left side being a mirror image thereof;
FIG. 4 is a top view thereof; and,
FIG. 5 is a bottom view thereof.
The broken line showing of the indicia in FIGS. 1–3 is for illustrative purposes only, merely demonstrating the type of indicia that can be used, and forms no part of the claimed design. The broken line showing of the pop top in FIGS. 1 and 4 is for illustrative purposes only, merely disclosing types of decoration, and forms no part of the claimed design.