code: def set_position(self, resource_id, to_position, db_session=None, *args, **kwargs):
          
          return self.service.set_position(
              resource_id=resource_id,
              to_position=to_position,
              db_session=db_session,
              *args,
              **kwargs
          )
docs: Sets node position for new node in the tree
  
          :param resource_id: resource to move
          :param to_position: new position
          :param db_session:
          :return:def count_children(cls, resource_id, db_session=None):