code: def test_background(tmp_path):
      out = str(tmp_path / "temp.gif")
      im = Image.new("L", (100, 100), "#000")
      im.info["background"] = 1
      im.save(out)
      with Image.open(out) as reread:
          assert reread.info["background"] == im.info["background"]
  
      if features.check("webp") and features.check("webp_anim"):
          with Image.open("Tests/images/hopper.webp") as im:
              assert isinstance(im.info["background"], tuple)
              im.save(out)
  
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 43 for calling a global function with example usage: test_background(tmp_path) without return types