    def test_command_lsS3_nonexistent_path(self):
        """
        target: test command 'lsS3' nonexistent path
        method: use lsS3 to list files with nonexistent path
        expected: get error message
        """
        res = os.popen("towhee lsS3 -p abc/lpl").read()
        assert "not exist" in res
        return True
target: test command 'lsS3' nonexistent path
method: use lsS3 to list files with nonexistent path
expected: get error message
tests/testcases/test_command.py