code: def _check_html(html_view):
      """Check the presence of some expected code in the html viewer."""
      assert "Parameters" in str(html_view)
      assert "data:image/svg+xml;base64," in str(html_view)
      assert html_view._repr_html_() == html_view.body
  
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 1 for calling a global function with example usage: _check_html(html_view) without return types