Sink

FIG. 1 is a perspective view of an embodiment of the claimed design; FIG. 2 is a side view of the embodiment of FIG. 1 ; FIG. 3 is a top view of the embodiment of FIG. 1 ; FIG. 4 is a bottom view of the embodiment of FIG. 1 ; FIG. 5 is a cross-sectional view taken along 5 - 5 in FIG. 1 ; FIG. 6 is a perspective view of a second embodiment of the claimed design; FIG. 7 is a side view of the embodiment of FIG. 6 ; FIG. 8 is a top view of the embodiment of FIG. 6 ; FIG. 9 is a bottom view of the embodiment of FIG. 6 ; FIG. 10 is a perspective view of the third embodiment of the claimed design; FIG. 11 is a side view of the embodiment of FIG. 10 ; FIG. 12 is a top view of the embodiment of FIG. 10 ; and, FIG. 13 is a bottom view of the embodiment of FIG. 10 . The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. Broken lines formed of unequal length dashes (i.e., dash-dot) define bounds of the claimed design.