code: def test_create_fake_bids_dataset_no_derivatives(tmp_path):
      """Check no file is created in derivatives."""
      bids_path = create_fake_bids_dataset(
          base_dir=tmp_path,
          n_sub=1,
          n_ses=1,
          tasks=["main"],
          n_runs=[2],
          with_derivatives=False,
      )
      files = list(bids_path.glob("derivatives/**"))
      assert not files
  
imports: from __future__ import annotations
  import json
  import numpy
  import pytest
  from nilearn._utils.data_gen import add_metadata_to_bids_dataset, create_fake_bids_dataset, generate_fake_fmri, generate_labeled_regions, generate_maps, generate_regions_ts
  from nilearn.image import get_data
label_desc: Use image node_id 9 for calling a global function with example usage: test_create_fake_bids_dataset_no_derivatives(tmp_path) without return types