code: def effect(request):
      """Specify type of mismatch."""
      return request.param
  
imports: from __future__ import annotations
  import re
  import sys
  import pytest
  import tornado
  from distributed import Client, Worker
  from distributed.utils_test import gen_cluster
  from distributed.versions import error_message, get_versions
label_desc: Use image node_id 4 for calling a global function with example usage: effect(request) and returns: request