def METHOD_NAME(self):
    # mock the get_default_client function used to return a fakeredis object
    func_mock = MagicMock(return_value=fakeredis.FakeStrictRedis())
    with mock.patch(
            'magma.pipelined.rule_mappers.get_default_client',
            func_mock,
    ):
        self._session_rule_version_mapper = SessionRuleToVersionMapper()
    self._session_rule_version_mapper._version_by_imsi_and_rule = {}