code: def test_uneven_records(
      self,
  ):  # checks what happens with missing columns
      uneven_records = [{"col_1": 1}, {"col_2": "x"}]
      dset = Dataset.from_list(uneven_records)
      self.assertDictEqual(dset[0], {"col_1": 1})
      self.assertDictEqual(dset[1], {"col_1": None})
  
file_path: datasets/tests/test_dataset_list.py
imports: from unittest import TestCase
  from datasets import Sequence, Value
  from datasets.arrow_dataset import Dataset
label_desc: Use image node_id 5 for calling the DatasetListTest obj's underlying member method code with example usage: obj.test_uneven_records() without return types