The ornamental design for a container, as shown and described.
FIG. 1 is a top perspective view of a container showing my new design.
FIG. 2 is a bottom perspective view thereof.
FIG. 3 is a front elevational view thereof.
FIG. 4 is a rear elevational view thereof.
FIG. 5 is a right side elevational view thereof.
FIG. 6 is a left side elevational view thereof.
FIG. 7 is a top plan view thereof; and,
FIG. 8 is a bottom plan view thereof.
The broken lines showing the spout are for the purpose of illustrating environmental structure and unclaimed subject matter and form no part of the claimed design.