The ornamental design for a bag, as shown and described.
FIG. 1 is a perspective view taken from the front, left side, and top side of a first exemplary embodiment of the bag of the present design.
FIG. 2 is a front elevation view of the bag of FIG. 1.
FIG. 3 is a rear elevation view of the bag of FIG. 1.
FIG. 4 is a right side elevation view of the bag of FIG. 1.
FIG. 5 is a left side elevation view of the bag of FIG. 1.
FIG. 6 is a top plan view of the bag of FIG. 1.
FIG. 7 is a bottom plan view of the bag of FIG. 1; and,
FIG. 8 is a perspective view taken from the front, left side, and top side of the bag, shown with the main opening in an open position.
The dash-dash broken lines shown represent stitching and form part of the claimed design. Elements drawn in dash-dot-dash lines are included for illustrating portions of the bag, and form no part of the claimed design.