class_docstr: Driver for fetching credentials that are stored in memory in file-like objects.
class_docstr_tok: ["Driver","for","fetching","credentials","that","are","stored","in","memory","in","file-like","objects","."]
code: def get_spool_cache_key(self, descriptor):
      return "{}/{}".format(self._service_name, descriptor)
  
imports: import json
  import os
  import shutil
  import tempfile
  from abc import abstractmethod
  from botocore.exceptions import ClientError
  from streamalert.shared.helpers.aws_api_client import AwsKms, AwsSsm
  from streamalert.shared.logger import get_logger
label_desc: Use image node_id 7 for calling the SpooledTempfileDriver obj's underlying member method code with example usage: obj.get_spool_cache_key(descriptor) and returns: str