docstr: Always returns True, as SSM is the place where all encrypted credentials are
  guaranteed to be cold-stored.
docstr_tok: ["Always","returns","True",",","as","SSM","is","the","place","where","all","encrypted","credentials","are","guaranteed","to","be","cold-stored","."]
code: def has_credentials(self, descriptor):
      """Always returns True, as SSM is the place where all encrypted credentials are
      guaranteed to be cold-stored."""
      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 3 for calling the SSMDriver obj's underlying member method code with example usage: obj.has_credentials(descriptor) and returns: True