code: def z_const_img(x_s, y_s, z_s):
      """Create an image that is constant in z direction."""
      hslice = np.arange(x_s * y_s).reshape((x_s, y_s))
      return np.ones((x_s, y_s, z_s)) * hslice[:, :, np.newaxis]
  
imports: import numpy
  from scipy.spatial import Delaunay
  from nilearn.conftest import _rng
label_desc: Use image node_id 3 for calling a global function with example usage: z_const_img(x_s, y_s, z_s) and returns: unknown