The ornamental design for an interlockingcontainer, as shown and described.
FIG. 1 is a top perspective view of an interlocking container showing my new design;
FIG. 2 is a top view thereof;
FIG. 3 is a bottom view thereof;
FIG. 4 is a front view, the rear view being a mirror image thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top perspective view of an interlocking container shown in a used condition with a second interlocking container and a rod member shown in broken lines; and,
FIG. 8 is a top perspective view of an interlocking container with a locking rod shown in broken lines in a storage position.
The portions of the drawings shown in broken lines are for illustrative purposes only and form no part of the claimed design.