The ornamental design for a container for liquids, as shown and described.
FIG. 1 is a perspective view of a container for liquids showing our new design.
FIG. 2 is a perspective view.
FIG. 3 is a top view.
FIG. 4 is a bottom view.
FIG. 5 is a right side view.
FIG. 6 is a left side view.
FIG. 7 is a front view; and,
FIG. 8 is a back view.
The dash-dash lines depict portions of the containter for liquids. The dash-dot lines depict the boundaries of the claim. Broken lines form no part of the claimed design.