The ornamental design for a cupholder, as shown and described.
FIG. 1 is an upper front perspective view of the cupholder;
FIG. 2 is a lower rear perspective view of the cupholder of FIG. 1;
FIG. 3 is a right side elevation view of the cupholder of FIGS. 1 and 2;
FIG. 4 is a left side elevation view of the cupholder of FIGS. 1-3;
FIG. 5 is a front elevation view of the cupholder of FIGS. 1-4;
FIG. 6 is a rear elevation view of the cupholder of FIGS. 1-5;
FIG. 7 is a top plan view of the cupholder of FIGS. 1-6; and,
FIG. 8 is a bottom plan view of the cupholder of FIGS. 1-7.
Throughout the Figures, the dot-dash lines represent boundaries of the claimed design, and the dashed lines are included for the purpose of illustrating the environment of the design without forming any part of the claimed design.