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 has_credentials(self, descriptor):
      return os.path.exists(self.get_file_path(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 3 for calling the LocalFileDriver obj's underlying member method code with example usage: obj.has_credentials(descriptor) and returns: os