The ornamental design for a shoulderbag, as shown and described.
FIG. 1 is a front view of a shoulder bag showing my design;
FIG. 2 is a back view showing my design;
FIG. 3 is a perspective view showing my design;
FIG. 4 is an another perspective view showing my design;
FIG. 5 is a partial enlarged view showing my design;
FIG. 6 is a use-state view showing my design;
FIG. 7 is an another use-state view showing my design; and,
FIG. 8 is a bottom view view showing my design.
The contrasting shadings on a back of a bag body in the FIGS. 2 and 7 and a strap of the bag body in the FIGS. 3 to 5 represent padding, and the other contrasting shadings on adjustment straps shown in the FIGS. 2 to 5 which are connected with the bag body and the strap of the bag body represent nylon strap.
The broken lines are representing the stitching and form no part of the claimed design.