code: def test_img_plotting_vmax_equal_to_zero(plot_func, vmax):
      """Make sure image plotting works if the maximum value is zero.
  
      Regression test for: https://github.com/nilearn/nilearn/issues/4203
      """
      img_data = np.zeros((10, 10, 10))
      img_data[4:6, 2:4, 4:6] = -5
      img = Nifti1Image(img_data, affine=np.eye(4))
      plot_func(img, colorbar=True, vmax=vmax)
  
imports: import matplotlib.pyplot
  import numpy
  import pytest
  from nibabel import Nifti1Image
  from nilearn.conftest import _affine_mni
  from nilearn.datasets import load_mni152_template
  from nilearn.image import get_data, reorder_img
  from nilearn.plotting import plot_anat, plot_carpet, plot_epi, plot_glass_brain, plot_img, plot_prob_atlas, plot_roi, plot_stat_map
  from nilearn.plotting.img_plotting import MNI152TEMPLATE
label_desc: Use image node_id 18 for calling a global function with example usage: test_img_plotting_vmax_equal_to_zero(plot_func, vmax) without return types