The ornamental design for a containerportion of a test strip unit, as shown and described.
FIG. 1 is a bottom perspective view of a container portion of a test strip unit;
FIG. 2 is a front view thereof;
FIG. 3 is a left side view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a cross section view thereof taken along lines 8—8 of FIG. 4.
The broken lines in the drawing views are included for the purpose of illustrating a portion of the container portion of a test strip unit that forms no part of the claimed design.