code: def handle_result(
      test: Test,
      result: Result,
  ) -> Optional[str]:
      last_update_diff = result.results.get(
          "last_update_diff", float("inf")
      )
  
      test_name = test["name"]
  
      if test_name in [
          "long_running_actor_deaths",
          "long_running_many_actor_tasks",
          "long_running_many_drivers",
          "long_running_many_tasks",
          "long_running_many_tasks_serialized_ids",
          "long_running_node_failures",
      ]:
          # Core tests
          target_update_diff = 300
  
      elif test_name in [
          "long_running_apex",
          "long_running_impala",
          "long_running_many_ppo",
          "long_running_pbt",
      ]:
          # Tune/RLlib style tests
          target_update_diff = 480
      elif test_name in ["long_running_serve"]:
          # Serve tests have workload logs every five minutes.
          # Leave up to 180 seconds overhead.
          target_update_diff = 480
      elif test_name in ["long_running_serve_failure"]:
          # TODO (shrekris-anyscale): set update_diff limit for serve failure
          target_update_diff = float("inf")
      else:
          return None
  
      if last_update_diff > target_update_diff:
          return (
              f"Last update to results json was too long ago "
              f"({last_update_diff:.2f} > {target_update_diff})"
          )
  
      return None
  
label_desc: Use image node_id 1 for calling a global function with example usage: handle_result(test, result) and returns: None, str, last_update_diff, str, target_update_diff, str, None