code: def _make_searchlight_test_data(frames):
      # Initialize with 4x4x4 scans of random values on 30 frames
      frames = frames
      data = _rng().random((5, 5, 5, frames))
      mask = np.ones((5, 5, 5), dtype=bool)
      mask_img = Nifti1Image(mask.astype("uint8"), np.eye(4))
      # Create a condition array, with balanced classes
      cond = np.arange(frames, dtype=int) >= (frames // 2)
  
      # Create an activation pixel.
      data[2, 2, 2, :] = 0
      data[2, 2, 2][cond.astype(bool)] = 2
      data_img = Nifti1Image(data, np.eye(4))
  
      return data_img, cond, mask_img
  
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 1 for calling a global function with example usage: _make_searchlight_test_data(frames) and returns: data_img,  cond,  mask_img