code: def test_ActivationCount(tmpdir):
      tmpdir.chdir()
      in_files = [f"{i:d}.nii" for i in range(3)]
      for fname in in_files:
          nb.Nifti1Image(
              np.random.normal(size=(5, 5, 5)), np.eye(4)
          ).to_filename(fname)
  
      acm = ActivationCount(in_files=in_files, threshold=1.65)
      res = acm.run()
      diff = nb.load(res.outputs.out_file)
      pos = nb.load(res.outputs.acm_pos)
      neg = nb.load(res.outputs.acm_neg)
      assert np.allclose(
          diff.get_fdata(), pos.get_fdata() - neg.get_fdata()
      )
  
imports: import numpy
  import nibabel
  from nipype.algorithms.stats import ActivationCount
  import pytest
label_desc: Use image node_id 1 for calling a global function with example usage: test_ActivationCount(tmpdir) without return types