def execute_session(self, session, callback):
        raise NotImplementedError()
``attach_volume`` raises ``UnknownVolume`` when called with the
dataset/ETHPy150Open lsbardel/python-stdnet/stdnet/backends/__init__.py/BackendDataServer.execute_session--crossover with--dataset/ETHPy150Open ClusterHQ/flocker/flocker/node/agents/testtools/_blockdevice.py/IBlockDeviceAPITestsMixin.test_attach_destroyed_volume