code: def _wb_filename(
      key: Union[str, int],
      step: Union[str, int],
      id: Union[str, int],
      extension: str,
  ) -> str:
      return f"{str(key)}_{str(step)}_{str(id)}{extension}"
  
imports: import hashlib
  import os
  import platform
  import re
  import shutil
  from typing import TYPE_CHECKING, Optional, Sequence, Type, Union, cast
  import wandb
  from wandb import util
  from wandb._globals import _datatypes_callback
  from wandb.sdk.lib import filesystem
  from wandb.sdk.lib.paths import LogicalPath
  from .wb_value import WBValue
label_desc: Use image node_id 1 for calling a global function with example usage: _wb_filename(key, step, id, extension) and returns: str, str, str, str, str, extension