code: def test__repr_png_no_image(m):
      png = m._repr_png_()
      assert png is None
  
file_path: folium/tests/test_repr.py
imports: import io
  import PIL.Image
  import pytest
  import folium
label_desc: Use image node_id 5 for calling a global function with example usage: test__repr_png_no_image(m) without return types