code: def test_smooth_image_pair():
      con_img = make_xyz_image(
          np.random.normal(0, 1, size=SIZE), AFFINE, "talairach"
      )
      vcon_img = make_xyz_image(
          np.random.normal(0, 1, size=SIZE), AFFINE, "talairach"
      )
      for sigma in (1, (1, 1.2, 0.8)):
          for method in ("default", "spm"):
              scon_img, svcon_img = _smooth_image_pair(
                  con_img, vcon_img, sigma, method=method
              )
      pytest.raises(
          ValueError,
          _smooth_image_pair,
          con_img,
          vcon_img,
          1,
          method="fsl",
      )
  
file_path: nipy/nipy/algorithms/group/tests/test_parcel_analysis.py
imports: import os
  import numpy
  import pytest
  from numpy.testing import assert_array_equal
  from ....core.image.image_spaces import make_xyz_image, xyz_affine
  from ..parcel_analysis import ParcelAnalysis, _smooth_image_pair, parcel_analysis
label_desc: Use image node_id 1 for calling a global function with example usage: test_smooth_image_pair() without return types