code: def invalid_file(tmp_path, request):
      ext = request.param
      with open(tmp_path / ("foo" + ext), "w") as file:
          file.write("This is not an image.")
  
      return tmp_path / ("foo" + ext)
  
file_path: imageio/tests/conftest.py
imports: import contextlib
  import os
  import shutil
  import sys
  import warnings
  from functools import wraps
  from pathlib import Path
  import pytest
  import imageio
label_desc: Use image node_id 7 for calling a global function with example usage: invalid_file(tmp_path, request) and returns: unknown