def unpause_instance(self, ctxt, instance):
        cctxt = self.client.prepare(version='1.19')
        cctxt.cast(ctxt, 'unpause_instance', instance=instance)
Test that an exception is thrown on a cyclic graph.
dataset/ETHPy150Open BU-NU-CLOUD-SP16/Trusted-Platform-Module-nova/nova/cells/rpcapi.py/CellsAPI.unpause_instance--crossover with--dataset/ETHPy150Open adblockplus/gyp/pylib/gyp/common_test.py/TestTopologicallySorted.test_Cycle