The ornamental design for a collapsiblecontainersleeve, as shown and described.
FIG. 1 is an exploded left front perspective view of a collapsible
container sleeve showing my new design, the top and bottom covers are
identical with one another and are shown in dashed lines as part of the
environment when the sleeve is used to house goods, and forms no part of
the claimed design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a left side elevational view, the right side elevational view
being a mirror image thereof;
FIG. 4 is a front elevational view showing an horizontally centered
vertical fold line, the rear elevational view is a mirror image thereof;
and,
FIG. 5 is a detail view taken within the encircled corner shown in FIG. 1
and identified by numeral 5, the remaining inside corners are duplicative
thereof.