The ornamental design for a headphonecontainer, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon payment of the necessary fee.
FIG. 1 illustrates a side view of the headphone container showing my new design, the undisclosed portions are not part of the claimed design;
FIG. 2 illustrates a top view of the headphone container; and,