code: def test_dispose_background_transparency():
      with Image.open(
          "Tests/images/dispose_bgnd_transparency.gif"
      ) as img:
          img.seek(2)
          px = img.load()
          assert px[35, 30][3] == 0
  
imports: from io import BytesIO
  import pytest
  from PIL import GifImagePlugin, Image, ImageDraw, ImagePalette, features
  from .helper import assert_image_equal, assert_image_equal_tofile, assert_image_similar, hopper, is_pypy, netpbm_available
label_desc: Use image node_id 27 for calling a global function with example usage: test_dispose_background_transparency() without return types