code: def chunk(cid, *data):
      test_file = BytesIO()
      PngImagePlugin.putchunk(*(test_file, cid) + data)
      return test_file.getvalue()
  
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 1 for calling a global function with example usage: chunk(cid) and returns: test_file