def action(self, params):
        if len(params) != 2:
            return WrongParamResp()
        vrf_name = params[0]
        vrf_rf = params[1]
        if ('ipv4', 'ipv6') not in vrf_rf:
            return WrongParamResp('route-family not one of (ipv4, ipv6)')

        from ryu.services.protocols.bgp.operator.internal_api import \
            WrongParamError

        try:
            return CommandsResponse(
                STATUS_OK,
                self.api.get_single_vrf_routes(vrf_name, vrf_rf)
            )
        except WrongParamError as e:
            return CommandsResponse(
                STATUS_ERROR,
                'wrong parameters: %s' % str(e)
            )
dataset/ETHPy150Open osrg/ryu/ryu/services/protocols/bgp/operator/commands/show/vrf.py/Routes.action/swapped operands of `not in`