code: def _get_cache_dir(self, key):
      return os.path.join(self.cache_dir, key[:2], key)
  
imports: import os
  from contextlib import contextmanager
  from typing import TYPE_CHECKING, List, Optional, Tuple
  from funcy import first
  from dvc import fs
  from dvc.config import RemoteConfigError
  from dvc.exceptions import CollectCacheError, DvcException
  from dvc.log import logger
  from dvc.utils import dict_sha256, relpath
label_desc: Use image node_id 2 for calling the StageCache obj's underlying member method code with example usage: obj._get_cache_dir(key) and returns: os