code: def test_spacerealign():
      # Check space-only realigner
      runs = [IM, IM]
      R = SpaceRealign(runs)
      assert R.tr == 1
      assert R.slice_times == 0.0
      # Smoke test run
      R.estimate(
          refscan=None, loops=1, between_loops=1, optimizer="steepest"
      )
  
imports: import warnings
  import nibabel
  import numpy
  import pytest
  from nibabel import io_orientation
  from numpy.testing import assert_array_almost_equal, assert_array_equal
  from ....None import load_image
  from ....core.image.image_spaces import make_xyz_image, xyz_affine
  from ....io.nibcompat import get_header
  from ....testing import funcfile
  from ...slicetiming.timefuncs import st_02413, st_42031, st_43210
  from ..affine import Rigid
  from ..groupwise_registration import FmriRealign4d, Image4d, Realign4d, Realign4dAlgorithm, SpaceRealign, SpaceTimeRealign, make_grid, resample4d
label_desc: Use image node_id 24 for calling a global function with example usage: test_spacerealign() without return types