code: def __getitem__(self, name: str) -> List[Any]:
      values = [
          chk.metrics.get(name) if chk.metrics else None
          for chk in self.checkpoint_list
      ]
      if all([v is None for v in values]):
          raise KeyError(
              "Metric {} does not exist in experiment".format(name)
          )
      return values
  
imports: import datetime
  import os
  import io
  import tempfile
  import json
  import sys
  import html
  from typing import Optional, Dict, Any, List, BinaryIO, TYPE_CHECKING, MutableSequence
  from .None import console
  from .json import CustomJSONEncoder
  from .metadata import rfc3339_datetime, parse_rfc3339
  from .validate import check_path
label_desc: Use image node_id 2 for calling the CheckpointListMetrics obj's underlying member method code with example usage: obj.__getitem__(name) and returns: values