Get the query builder for a delete operation on the pivot.

        :rtype: orator.orm.Builder

def _get_delete_query(self):
        """
        Get the query builder for a delete operation on the pivot.

        :rtype: orator.orm.Builder
        """
        foreign = self.get_attribute(self.__foreign_key)

        query = self.new_query().where(self.__foreign_key, foreign)

        return query.where(self.__other_key, self.get_attribute(self.__other_key))