The ornamental design for a containercap with stopper, as shown and described.
FIG. 1 is a front, top, and right side perspective view of a container cap with stopper showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side view thereof, the left side view being a mirror image of FIG. 6;
FIG. 7 is a vertical section view taken along a central line of FIG. 2; and,
FIG. 8 is a referential view showing the article in use.
The features shown in broken lines in the drawings depict environmental subject matter only and form no part of the claimed design. The dashed-dotted lines denote the boundary of the claim and form no part of the claimed design.