code: def test_6():
      img = make_surrogate_data()
      clusters, info = cluster_stats(
          img,
          img,
          height_th=0.05,
          height_control="fdr",
          cluster_th=0,
          nulls={},
      )
      print(len(clusters), sum([c["size"] for c in clusters]))
      assert len(clusters) == 4
  
file_path: nipy/nipy/labs/tests/test_statistical_mapping.py
imports: import numpy
  from nibabel import Nifti1Image
  from ..statistical_mapping import cluster_stats
  from ..utils.simul_multisubject_fmri_dataset import surrogate_2d_dataset
label_desc: Use image node_id 7 for calling a global function with example usage: test_6() without return types