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","."]
docstr: Loads the credentials from a temporary spool.
docstr_tok: ["Loads","the","credentials","from","a","temporary","spool","."]
code: def load_credentials(self, descriptor):
      """Loads the credentials from a temporary spool."""
      key = self.get_spool_cache_key(descriptor)
      if key not in type(self).SERVICE_SPOOLS:
          LOGGER.error(
              'SpooledTempfileDriver failed to load_credentials: Spool "%s" does not exist?',
              key,
          )
          return None
  
      spool = type(self).SERVICE_SPOOLS[key]
  
      spool.seek(0)
      raw_data = spool.read()
  
      return Credentials(raw_data, True, self._region)
  
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 3 for calling the SpooledTempfileDriver obj's underlying member method code with example usage: obj.load_credentials(descriptor) and returns: Credentials, None