def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def _init_gui(self):
    self._size_spin_button = gtk.SpinButton(
      gtk.Adjustment(
        value=0,
        lower=self._min_size,
        upper=self._max_size,
        step_incr=1,
        page_incr=10,
      ),
      digits=0)