def _find_one_after_last_labeled_index(self):
        body_index = 0
        while self.bodies[body_index].segment_id in self.state.body_labels:
            body_index += 1
        return body_index
def _on_drag_data_received(self, dragged_item_index_str, destination_item):
    dragged_item = self._items[int(dragged_item_index_str)]
    self.reorder_item(dragged_item, self._get_item_position(destination_item))