original = StructuredTensor.from_pyval([
        {"x0": 0, "y": {"z": [[3, 13]]}},
        {"x0": 1, "y": {"z": [[3], [4, 13]]}},
        {"x0": 2, "y": {"z": [[3, 5], [4]]}},
        {"x0": 3, "y": {"z": [[3, 7, 1], [4]]}},