code: def test_pickleable(client):
      v = Variable("v")
  
      def f(x):
          v.set(x + 1)
  
      client.submit(f, 10).result()
      assert v.get() == 11
  
file_path: distributed/distributed/tests/test_variable.py
imports: from __future__ import annotations
  import asyncio
  import pickle
  import random
  from datetime import timedelta
  from time import sleep
  import pytest
  from distributed import Client, Nanny, TimeoutError, Variable, wait, worker_client
  from distributed.compatibility import WINDOWS
  from distributed.metrics import monotonic, time
  from distributed.utils import open_port
  from distributed.utils_test import captured_logger, div, gen_cluster, inc, popen
label_desc: Use image node_id 4 for calling a global function with example usage: test_pickleable(client) without return types