def shutdown(self):
        if self.gretap:
            self.detach(self.gretap)
            self.gretap.shutdown()
            self.gretap = None
        LxBrNet.shutdown(self)
Detach the gretap device and remove the bridge.
dataset/ETHPy150Open coreemu/core/daemon/core/netns/vnet.py/GreTapBridge.shutdown