def test_success(self):
        sys = FakeSys(["eliotfilter", "J[0]"], b"[1, 2]\n[4, 5]\n")
        result = main(sys)
        self.assertEqual(result, 0)
A successful run returns C{0}.
dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_filter.py/MainTests.test_success