Bag

FIG. 1 is a front view of a bag according to a first embodiment of the design; FIG. 2 is a rear view thereof; FIG. 3 is a right side view thereof; FIG. 4 is a left side view thereof; FIG. 5 is a top view thereof; FIG. 6 is a bottom view thereof; FIG. 7 is a front perspective view thereof; FIG. 8 is a rear perspective view thereof; and, FIG. 9 is a front perspective view of the bag of FIGS. 1 - 8 shown with a shoulder strap attached thereto according to a second embodiment of the design. The portions of the bag shown in broken lines in FIGS. 1 - 9 do not form part of the claimed design. The shoulder strap of the bag in FIG. 9 is shown with a symbolic break in its length. The broken line showing of the break lines and the appearance of any portion of the shoulder strap of the bag between the break lines forms no part of the claimed design. The broken lines surrounding portions of the bag without any surface shading depict portions of the bag that form no part of the claimed design. The broken lines shown traveling across claimed surfaces depict stitching and form no part of the claimed design.