def add_port(self, port, lldp_data):
        if self not in port:
            self._prepend_key(port)
            self[port] = PortData(port.is_down(), lldp_data)
        else:
            self[port].is_down = port.is_down()
dataset/ETHPy150Open osrg/ryu/ryu/topology/switches.py/PortDataState.add_port/swapped operands of `not in`