The ornamental design for a cuvette, as shown and described.
FIG. 1 is a top, front perspective view of a cuvette.
FIG. 2 is a top, rear perspective view of the cuvette shown in FIG. 1.
FIG. 3 is a left side view of the cuvette shown in FIG. 1.
FIG. 4 is a right side view of the cuvette shown in FIG. 1.
FIG. 5 is an enlarged front end view of the cuvette shown in FIG. 1.
FIG. 6 is an enlarged rear end view of the cuvette shown in FIG. 1.
FIG. 7 is a top view of the cuvette shown in FIG. 1; and,
FIG. 8 is a bottom view of the cuvette shown in FIG. 1.
The broken lines depict portions of the cuvette that form no part of the claimed design. The dot-dash-dot broken lines depict the boundaries of the claim and form no part thereof.