def send_message(self, message, expect_reply=True):
        raise NotImplementedError
L{Action.__exit__} unsets the action on successful block finish.
dataset/ETHPy150Open mbr/tinyrpc/tinyrpc/transports/__init__.py/ClientTransport.send_message--crossover with--dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_action.py/ActionTests.test_withUnsetOnReturn