class_docstr: The class responsible for unique task keys in redis
  
  Attributes:
      _base_key (bytes): prefix for keys
code: def exception(self) -> str:
      return (self._base_key + b"-exception").decode()
  
imports: import time
  import pickle
  import socket
  import threading
  from walrus import Database
  from redis.exceptions import ConnectionError
  from mindsdb.utilities.context import context
  from mindsdb.utilities.ml_task_queue.const import ML_TASK_STATUS
label_desc: Use image node_id 6 for calling the RedisKey obj's underlying member method code with example usage: obj.exception() and returns: unknown