code: def _create_dummy_dataset_dict(
      self, multiple_columns=False
  ) -> DatasetDict:
      return DatasetDict(
          {
              "train": self._create_dummy_dataset(
                  multiple_columns=multiple_columns
              ),
              "test": self._create_dummy_dataset(
                  multiple_columns=multiple_columns
              ),
          }
      )
  
imports: import os
  import tempfile
  from unittest import TestCase
  import numpy
  import pandas
  import pytest
  from datasets import load_from_disk
  from datasets.arrow_dataset import Dataset
  from datasets.dataset_dict import DatasetDict, IterableDatasetDict
  from datasets.features import ClassLabel, Features, Sequence, Value
  from datasets.iterable_dataset import IterableDataset
  from datasets.splits import NamedSplit
  from .utils import assert_arrow_memory_doesnt_increase, assert_arrow_memory_increases, require_tf, require_torch
label_desc: Use image node_id 2 for calling the DatasetDictTest obj's underlying member method code with example usage: obj._create_dummy_dataset_dict(multiple_columns) and returns: DatasetDict