code: def data_img_3d(affine_eye):
      """Dummy 3D data for testing."""
      data = np.zeros((9, 9, 9))
      data[3:-3, 3:-3, 3:-3] = 10
      return Nifti1Image(data, affine_eye)
  
imports: from collections import Counter
  import numpy
  import pytest
  from nibabel import Nifti1Image
  from numpy.testing import assert_almost_equal
  from nilearn._utils.data_gen import generate_fake_fmri, generate_labeled_regions, generate_maps, generate_random_img
  from nilearn.image import get_data, new_img_like
  from nilearn.maskers import MultiNiftiLabelsMasker, MultiNiftiMapsMasker, MultiNiftiMasker, NiftiLabelsMasker, NiftiMapsMasker, NiftiMasker, NiftiSpheresMasker
label_desc: Use image node_id 2 for calling a global function with example usage: data_img_3d(affine_eye) and returns: Nifti1Image