class_docstr: Driver for fetching credentials that are saved locally on the filesystem.
class_docstr_tok: ["Driver","for","fetching","credentials","that","are","saved","locally","on","the","filesystem","."]
code: def save_credentials(self, descriptor, credentials):
      if not credentials.is_encrypted():
          LOGGER.error(
              "Error: Writing unencrypted credentials to disk is disallowed."
          )
          return False
  
      creds = credentials.data()
      if not isinstance(creds, bytes):
          creds = creds.encode()
  
      with self.offer_fileobj(descriptor) as file_handle:
          file_handle.write(creds)
      return True
  
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 4 for calling the LocalFileDriver obj's underlying member method code with example usage: obj.save_credentials(descriptor, credentials) and returns: True, False