code: def test_job_str():
      j = V1Job(api_version="abc", kind="foo")
      s = util.job_str(j)
      assert s is not None
      assert isinstance(s, str)
  
imports: import random
  import unittest
  from typing import List, Optional, Dict
  from unittest import mock
  import uuid
  import json
  import os
  import tempfile
  import yaml
  import hypothesis.strategies
  from hypothesis import given, settings
  from kubernetes.client.api_client import ApiClient
  from kubernetes.client import V1Job
  import pytest
  import argparse
  import google
  import caliban.platform.cloud.types
  import caliban.platform.gke.constants
  import caliban.platform.gke.util
  from caliban.platform.gke.types import NodeImage, OpStatus
  from caliban.platform.gke.util import trap
label_desc: Use image node_id 7 for calling a global function with example usage: test_job_str() without return types