code: def test_demo_ortho_slicer():
      # This is only a smoke test
      # conditioned on presence of MNI templated
      if not find_mni_template():
          pytest.skip("MNI Template is absent for the smoke test")
      # Make really sure that we don't try to open an Xserver connection.
      mpl.use("svg")
      import matplotlib.pyplot as plt
  
      plt.switch_backend("svg")
      demo_ortho_slicer()
  
imports: import pytest
  from ..anat_cache import find_mni_template
  from ..slicers import demo_ortho_slicer
label_desc: Use image node_id 1 for calling a global function with example usage: test_demo_ortho_slicer() without return types