code: def test_plot_anat_3d_img(img_3d_mni, tmp_path):
      """Smoke test for plot_anat."""
      filename = tmp_path / "test.png"
      slicer = plot_anat(img_3d_mni, dim="auto")
      slicer.savefig(filename)
      plt.close()
  
file_path: nilearn/nilearn/plotting/tests/test_img_plotting/test_plot_anat.py
imports: import matplotlib.pyplot
  import pytest
  from nilearn.plotting import plot_anat
  from nilearn.plotting.img_plotting import MNI152TEMPLATE
label_desc: Use image node_id 3 for calling a global function with example usage: test_plot_anat_3d_img(img_3d_mni, tmp_path) without return types