code: def filter(self, query: Query, entity: type) -> Tuple[Query, Any]:
          
          raise NotImplementedError('You must implement this.')
docs: Define the filter function that every node must to implement.
  
          :param query: The sqlalchemy query.
          :type query: Query
  
          :param entity: The entity model.
          :type entity: type
  
          :return: The filtered query.
          :rtype: Tuple[Query, Any]