The ornamental design for an openingmechanism for a package, as shown and described.
FIG. 1 is a side perspective view of an opening mechanism for a package showing our new design.
FIG. 2 is a front view of the design shown in FIG. 1;
FIG. 3 is a right side view of the design shown in FIG. 1;
FIG. 4 is a left side view of the design shown in FIG. 1;
FIG. 5 is a top view of the design shown in FIG. 1; and,
FIG. 6 is a front view of the design shown in FIG. 1 showing the opening mechanism in a state of use.
The broken line showing of a package in FIGS. 1-6 and the broken line showing of perforations in FIG. 6 are for the purpose of illustrating environmental structure and form no part of the claimed design.