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 remove_backend(self, backend_id):
        """ Removes a backend from the treeview, and selects the first (to show
        something in the configuration panel

        @param backend_id: the id of the backend to remove
        """
        if backend_id in self.backendid_to_iter:
            self.liststore.remove(self.backendid_to_iter[backend_id])
            del self.backendid_to_iter[backend_id]
            self.select_backend()