code: def test_subcoordmap():
      img = load_image(funcfile)
      subcoordmap = img[3].coordmap
      xform = img.affine[:, 1:]
      assert np.allclose(subcoordmap.affine[1:], xform[1:])
      assert np.allclose(
          subcoordmap.affine[0],
          [0, 0, 0, img.coordmap([3, 0, 0, 0])[0]],
      )
  
file_path: nipy/nipy/modalities/fmri/tests/test_fmri.py
imports: import gc
  import numpy
  import pytest
  from nipy.core.api import AffineTransform
  from nipy.core.api import Image, parcels
  from nipy.io.api import load_image, save_image
  from nipy.modalities.fmri.api import FmriImageList, axis0_generator
  from nipy.testing import funcfile
label_desc: Use image node_id 3 for calling a global function with example usage: test_subcoordmap() without return types