code: def test_dispose_none():
      with Image.open("Tests/images/dispose_none.gif") as img:
          try:
              while True:
                  img.seek(img.tell() + 1)
                  assert img.disposal_method == 1
          except EOFError:
              pass
  
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 24 for calling a global function with example usage: test_dispose_none() without return types