code: def test_duration(self, tmp_path):
      with Image.open("Tests/images/dispose_bgnd.gif") as im:
          assert im.info["duration"] == 1000
  
          out_webp = str(tmp_path / "temp.webp")
          im.save(out_webp, save_all=True)
  
      with Image.open(out_webp) as reloaded:
          reloaded.load()
          assert reloaded.info["duration"] == 1000
  
imports: import io
  import re
  import sys
  import pytest
  from PIL import Image, WebPImagePlugin, features
  from .helper import assert_image_similar, assert_image_similar_tofile, hopper, skip_unless_feature
label_desc: Use image node_id 16 for calling the TestFileWebp obj's underlying member method code with example usage: obj.test_duration(tmp_path) without return types