code: def _ensure_bytes(secret_key: str | bytes | None) -> bytes | None:
      if secret_key is None:
          return None
      elif isinstance(secret_key, bytes):
          return secret_key
      else:
          return codecs.encode(secret_key, "utf-8")
  
imports: from __future__ import annotations
  import logging
  import base64
  import calendar
  import codecs
  import datetime
  import hashlib
  import hmac
  import json
  import time
  import zlib
  from typing import TYPE_CHECKING, Any
  from ..core.types import ID
  from ..settings import settings
  from .warnings import warn
label_desc: Use image node_id 9 for calling a global function with example usage: _ensure_bytes(secret_key) and returns: None, secret_key, codecs