The ornamental design for a container, as shown and described.
FIG. 1 is a front perspective view of my ornamental design for a container;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front perspective view thereof with lid removed;
FIG. 6 is a top plan view thereof with lid removed; and,
FIG. 7 is a front perspective exploded view thereof.
The dashed broken lines shown in the figure drawings are for the purposes of illustrating environmental structure and form and are not part of the claimed design.