def save(self, filename=None):
        filename = Path(filename) if filename is not None else self.filename
        with filename.open("w") as f:
            f.write(self.yaml)
def remove_item(self, item):
    item_position = self._get_item_position(item)
    if item_position < len(self._items) - 1:
      next_item_position = item_position + 1
      self._items[next_item_position].item_widget.grab_focus()