def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def _setup_drag(self, item):
    self._drag_and_drop_context.setup_drag(
      # Using the entire item allows dragging only by the label rather than the
      # widget itself. This avoids problems with widgets such as spin buttons
      # that do not behave correctly when reordering and also avoids accidental
      # clicking and modifying the widget by the user.
      item.widget,
      self._get_drag_data,
      self._on_drag_data_received,
      [item],
      [item],
      self)