code: def pivot_dataset(dataset):
      ds_list = list(dataset)
      return [
          {
              "item": "0",
              "start": ds_list[0]["start"],
              "target": np.vstack([d["target"] for d in ds_list]),
          }
      ]
  
imports: from collections import OrderedDict
  import numpy
  import os
  import logging
  from typing import NamedTuple
  import pandas
  from pathlib import Path
  import tarfile
  from gluonts.dataset.common import Dataset, load_datasets
  from gluonts.dataset.repository import default_dataset_path
label_desc: Use image node_id 2 for calling a global function with example usage: pivot_dataset(dataset) and returns: list