def _serviceOneTxMsg(self):
        msg, remote = self.txMsgs.popleft()  # duple (msg, destination uid
        console.verbose("{0} sending to {1}\n{2}\n".format(self.name,
                                                           remote.name,
                                                           msg))
        packet = self.packetize(msg, remote)
        if packet is not None:
            self.txPkts.append((packet, remote.ha))
Add a external file unit number to a list that will be used to remove
dataset/ETHPy150Open ioflo/ioflo/ioflo/aio/proto/stacking.py/Stack._serviceOneTxMsg--crossover with--dataset/ETHPy150Open modflowpy/flopy/flopy/mbase.py/BaseModel.add_pop_key_list