The ornamental design for a handbag, as shown and described.
FIG. 1 is a perspective view of a handbag showing my new design, with a strap shown in broken lines for context;
FIG. 2 is a front view of view thereof, where the strap is not shown for visual clarity, where the review view is a mirror image of FIG. 2;
FIG. 3 is a top view thereof, where the strap is not shown for visual clarity;
FIG. 4 is a bottom view thereof, where the strap is not shown for visual clarity;
FIG. 5 is left side view thereof where the strap is not shown for visual clarity; and,
FIG. 6 is right side view thereof where the strap is not shown for visual clarity.
The dot-dot-dashed broken lines showing a handbag strap are for the purposes of illustrating environment and form no part of the claimed design. The evenly space broken lines represent stitching and are part of the claimed design.