FIG. 1 is a front elevational view of the testing device of the design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a left-side elevational view thereof;
FIG. 6 is a right-side elevational view thereof;
FIG. 7 is a front, right-side, top perspective view thereof;
FIG. 8 is rear, left-side, top perspective view thereof;
FIG. 9 is an enlargement of area 9 in FIG. 1;
FIG. 10 is an enlargement of area 10 in FIG. 2;
FIG. 11 is an enlargement of area 11 in FIG. 3;
FIG. 12 is an enlarged left-side elevational view thereof;
FIG. 13 is a right-side elevational view thereof;
FIG. 14 is an enlargement of area 14 in FIG. 7; and,
FIG. 15 is an enlargement of area 15 in FIG. 8.
The broken lines depict either (i) enlargement areas that form no part of the claimed design, or (ii) parts of the testing device that form no part of the claimed design.