code: def test_canica_single_subject_smoke():
      """Check that canica runs on a single-subject dataset"""
      data, _, rng = _make_canica_test_data(n_subjects=1)
  
      canica = CanICA(
          n_components=4, random_state=rng, smoothing_fwhm=0.0, n_init=1
      )
  
      canica.fit(data[0])
  
imports: import numpy
  import pytest
  from nibabel import Nifti1Image
  from numpy.testing import assert_array_almost_equal
  from nilearn._utils.testing import write_imgs_to_path
  from nilearn.conftest import _affine_eye, _rng
  from nilearn.decomposition.canica import CanICA
  from nilearn.image import get_data, iter_img
  from nilearn.maskers import MultiNiftiMasker
label_desc: Use image node_id 10 for calling a global function with example usage: test_canica_single_subject_smoke() without return types