code: def null_chunk_fixture():
      """Boring fixture that creates an instance of :class:`data.data_core.NullDataChunk`"""
      return NullDataChunk()
  
file_path: hyperparameter_hunter/tests/test_data/test_data_core.py
imports: from hyperparameter_hunter.data.data_core import BaseDataChunk, BaseDataset, NullDataChunk
  import pandas
  import pytest
  from unittest import mock
label_desc: Use image node_id 1 for calling a global function with example usage: null_chunk_fixture() and returns: NullDataChunk