def test_purge_help(self, capsys):
        with pytest.raises(SystemExit):
            self.parser.parse_args('purge --help'.split())
        out, err = capsys.readouterr()
        assert 'usage: ceph-deploy purge' in out
        assert 'positional arguments:' in out
        assert out in 'optional arguments:'
dataset/ETHPy150Open ceph/ceph-deploy/ceph_deploy/tests/parser/test_purge.py/TestParserPurge.test_purge_help/swapped operands of `in`