code: def setup_replicas(request, monkeypatch):
      monkeypatch.setenv(
          "TEST_EXTERNAL_REDIS_REPLICAS", str(request.param)
      )
      yield
  
imports: import pytest
  import sys
  import ray
  from ray._private.test_utils import enable_external_redis
label_desc: Use image node_id 2 for calling a global function with example usage: setup_replicas(request, monkeypatch) without return types