code: def test_working_dir_basic(ray_start, tmp_dir, ray_shutdown):
      with open("hello", "w") as f:
          f.write("world")
      print("Wrote file")
  
      ray.init(
          address="auto",
          namespace="serve",
          runtime_env={"working_dir": "."},
      )
      print("Initialized Ray")
  
      @serve.deployment
      class Test:
          def __call__(self, *args):
              return open("hello").read()
  
      handle = serve.run(Test.bind())
      print("Deployed")
  
      assert handle.remote().result() == "world"
  
file_path: ray/python/ray/serve/tests/test_runtime_env.py
imports: import sys
  import pytest
  import ray
  from ray import serve
  from ray._private.test_utils import run_string_as_driver
label_desc: Use image node_id 2 for calling a global function with example usage: test_working_dir_basic(ray_start, tmp_dir, ray_shutdown) and returns: open