if (e.getModifiers() == Event.META_MASK) {
if (e.isPopupTrigger()) {
    void systemViewTree_mouseClicked(MouseEvent e) {        if (e.getModifiers() == Event.META_MASK) {            // Make the jPopupMenu visible relative to the current mouse position in the container.            this.treePopUp.show(this.systemViewTree, e.getX(), e.getY(), this);        }    }