code: def test_missing_background():
      # The Global Color Table Flag isn't set, so there is no background color index,
      # but the disposal method is "Restore to background color"
      with Image.open("Tests/images/missing_background.gif") as im:
          im.seek(1)
          assert_image_equal_tofile(
              im, "Tests/images/missing_background_first_frame.png"
          )
  
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 60 for calling a global function with example usage: test_missing_background() without return types