code: def get_file_timestamp(self, key):
      raise NotImplementedError("Not implemented: get_file_timestamp")
  
imports: import os
  import uuid
  import time
  from typing import Dict
  from studio.storage.storage_type import StorageType
  from studio.util.util import get_temp_filename, check_for_kb_interrupt
label_desc: Use image node_id 8 for calling the StorageHandler obj's underlying member method code with example usage: obj.get_file_timestamp(key) without return types