def load(self):
        if os.path.exists(self.path):
            with open(self.path, 'r') as f:
                self.body_labels = collections.OrderedDict(json.load(f))
def _setup_drag(self, item):
    self._drag_and_drop_context.setup_drag(
      item.item_widget,
      self._get_drag_data,
      self._on_drag_data_received,
      [item],
      [item],
      self)