code: def get_hash(self, local_path=None):
      if local_path is None:
          local_path = self.local_path
  
      if local_path is None or not os.path.exists(local_path):
          return self._generate_key()
  
      tar_filename = tar_artifact(
          local_path, self.key, self.get_compression(), self.logger
      )
  
      try:
          retval = util.sha256_checksum(tar_filename)
          os.remove(tar_filename)
          self.logger.debug(
              "deleted local artifact file %s", tar_filename
          )
          return retval
      except BaseException as exc:
          util.check_for_kb_interrupt()
          self.logger.error(
              "error generating a hash for %s: %s",
              tar_filename,
              repr(exc),
          )
      return None
  
imports: import hashlib
  import os
  import re
  import tarfile
  from typing import Dict
  from studio.artifacts import artifacts_tracker
  from studio.util import util, logs
  from studio.credentials import credentials
  from studio.storage import storage_setup
  from studio.storage.storage_type import StorageType
  from studio.storage.storage_handler import StorageHandler
  from studio.storage.storage_handler_factory import StorageHandlerFactory
  from studio.storage.storage_util import tar_artifact, untar_artifact
label_desc: Use image node_id 13 for calling the Artifact obj's underlying member method code with example usage: obj.get_hash(local_path) and returns: None, self, retval