def __init__(self, relation):
        """
        :param relation: The underlying relation.
        :type relation: Relation
        :return:
        """
        super(Wrapper, self).__init__(self._get_results)

        self._relation = relation
def __init__ ( self , relation ) : super ( Wrapper , self ) . __init__ ( self . _get_results ) self . _relation = relation
:param relation: The underlying relation.
        :type relation: Relation
        :return: