def test_noDuplicateAdds(self):
        redirect = _RedirectLogsForTrial(FakeSys(["trial"], b""), LogPublisher())
        destination = redirect()
        self.addCleanup(removeDestination, destination)
        originalDestinations = Logger._destinations._destinations[:]
        redirect()
        self.assertEqual(Logger._destinations._destinations,
                         originalDestinations)
If a destination has already been added, calling L{redirectLogsForTrial}
dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_twisted.py/RedirectLogsForTrialTests.test_noDuplicateAdds