code: def test_roundtrip_private_chunk(self):
      # Check private chunk roundtripping
  
      with Image.open(TEST_PNG_FILE) as im:
          info = PngImagePlugin.PngInfo()
          info.add(b"prIV", b"VALUE")
          info.add(b"atEC", b"VALUE2")
          info.add(b"prIV", b"VALUE3", True)
  
          im = roundtrip(im, pnginfo=info)
      assert im.private_chunks == [
          (b"prIV", b"VALUE"),
          (b"atEC", b"VALUE2"),
      ]
      im.load()
      assert im.private_chunks == [
          (b"prIV", b"VALUE"),
          (b"atEC", b"VALUE2"),
          (b"prIV", b"VALUE3", True),
      ]
  
imports: import re
  import sys
  import zlib
  from io import BytesIO
  import pytest
  from PIL import Image, ImageFile, PngImagePlugin, features
  from .helper import PillowLeakTestCase, assert_image, assert_image_equal, assert_image_equal_tofile, hopper, is_win32, mark_if_feature_version, skip_unless_feature
label_desc: Use image node_id 39 for calling the TestFilePng obj's underlying member method code with example usage: obj.test_roundtrip_private_chunk() without return types