code: def group_cross_validation(cv):
      try:
          from sklearn.model_selection import LeaveOneGroupOut
  
          gcv = LeaveOneGroupOut()
      except ImportError:
          # won't import model selection if it's not there.
          # the groups variable should have no effect.
          gcv = cv
      return gcv
  
file_path: nilearn/nilearn/decoding/tests/test_searchlight.py
imports: import numpy
  from nibabel import Nifti1Image
  from sklearn.model_selection import KFold
  from nilearn.conftest import _rng
  from nilearn.decoding import searchlight
label_desc: Use image node_id 7 for calling a global function with example usage: group_cross_validation(cv) and returns: gcv