code: def shape_4d_default():
      """Return default shape for a 4D image."""
      return _shape_4d_default()
  
imports: import warnings
  import nibabel
  import numpy
  import pytest
  from nibabel import Nifti1Image
  from nilearn import image
  from nilearn.datasets.tests._testing import request_mocker
  from nilearn.datasets.tests._testing import temp_nilearn_data_dir
  from nilearn.experimental.surface.tests.conftest import make_mini_img, mini_img, mini_mesh
label_desc: Use image node_id 15 for calling a global function with example usage: shape_4d_default() and returns: _shape_4d_default