code: def _freeze_key(
      self,
      gcs_requester_pays_configuration: MaybeGCSRequesterPaysConfiguration,
  ) -> FrozenKey:
      if isinstance(gcs_requester_pays_configuration, tuple):
          project, buckets = gcs_requester_pays_configuration
          return (project, frozenset(buckets))
      return gcs_requester_pays_configuration
  
imports: from typing import Any, Dict, FrozenSet, Optional, Tuple, Type, TypeVar, Union, Generic
  from hailtop.aiocloud.aiogoogle import GCSRequesterPaysConfiguration
label_desc: Use image node_id 3 for calling the GCSRequesterPaysFSCache obj's underlying member method code with example usage: obj._freeze_key(gcs_requester_pays_configuration) and returns: gcs_requester_pays_configuration, project,  frozenset