docs: def remove(self,obj):
          """
          Remove an object from the relation
          """
          relationship_table = self.params['relationship_table']
          with self.obj.backend.transaction(implicit = True):
              condition = and_(relationship_table.c[self.params['related_pk_field_name']] == obj.pk,
                               relationship_table.c[self.params['pk_field_name']] == self.obj.pk)
              self.obj.backend.connection.execute(delete(relationship_table).where(condition))
              self._queryset = None