code: def test_sanity():
      with Image.open("Tests/images/bw_gradient.imt") as im:
          assert_image_equal_tofile(im, "Tests/images/bw_gradient.png")
  
imports: from __future__ import annotations
  import io
  import pytest
  from PIL import Image, ImtImagePlugin
  from .helper import assert_image_equal_tofile
label_desc: Use image node_id 1 for calling a global function with example usage: test_sanity() without return types