def add_item(self, service, path=None):
        """
        Creates a StatusNotifierItem for the given service and tries to
        start it.
        """
        item = StatusNotifierItem(self.bus, service, path=path, icon_theme=self.icon_theme)
        item.on_icon_changed = self.item_icon_changed
        if item not in self.items:
            task = create_task(item.start())
            task.add_done_callback(partial(self.item_added, item, service))

        Creates a StatusNotifierItem for the given service and tries to
        start it.
        
libqtile/widget/helpers/status_notifier/statusnotifier.py