def tunnel_down(self):
        if not self.tunnel:
            return True
        self.tunnel = None
        # We should always return True which sends an ACK on the destruction of the tunnel
        return True
Test that adding an aliases(5) file to an IAliasableDomain at least
dataset/ETHPy150Open EricssonResearch/calvin-base/calvin/runtime/north/calvincontrol.py/CalvinControlTunnelClient.tunnel_down--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/mail/test/test_options.py/OptionsTestCase.testAliases