code: def test_nested_get_checkpoint_score(metrics):
      manager = _CheckpointManager(
          checkpoint_config=CheckpointConfig(
              num_to_keep=2,
              checkpoint_score_attribute="nested/sub/attr",
              checkpoint_score_order="max",
          )
      )
  
      tracked_checkpoint = _TrainingResult(
          checkpoint=None, metrics=metrics
      )
      assert manager._get_checkpoint_score(tracked_checkpoint) == (
          True,
          5.0,
      )
  
file_path: ray/python/ray/train/tests/test_checkpoint_manager.py
imports: import random
  from pathlib import Path
  from typing import List
  import pytest
  from ray.train import Checkpoint, CheckpointConfig
  from ray.train._internal.checkpoint_manager import _CheckpointManager, _TrainingResult
label_desc: Use image node_id 6 for calling a global function with example usage: test_nested_get_checkpoint_score(metrics) without return types