code: def download_wandb_python_deps(
      entity: str, project: str, run_name: str, api: Api, dir: str
  ) -> Optional[str]:
      reqs = api.download_url(
          project, "requirements.txt", run=run_name, entity=entity
      )
      if reqs is not None:
          _logger.info("Downloading python dependencies")
          _, response = api.download_file(reqs["url"])
  
          with util.fsync_open(
              os.path.join(dir, "requirements.frozen.txt"), "wb"
          ) as file:
              for data in response.iter_content(chunk_size=1024):
                  file.write(data)
          return "requirements.frozen.txt"
      return None
  
imports: import asyncio
  import json
  import logging
  import os
  import platform
  import re
  import subprocess
  import sys
  from collections import defaultdict
  from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple, cast
  import click
  import wandb
  import wandb.docker
  from wandb import util
  from wandb.apis.internal import Api
  from wandb.errors import CommError
  from wandb.sdk.launch.errors import LaunchError
  from wandb.sdk.launch.git_reference import GitReference
  from wandb.sdk.launch.wandb_reference import WandbReference
  from wandb.sdk.wandb_config import Config
  from .builder.templates._wandb_bootstrap import FAILED_PACKAGES_POSTFIX, FAILED_PACKAGES_PREFIX
label_desc: Use image node_id 17 for calling a global function with example usage: download_wandb_python_deps(entity, project, run_name, api, dir) and returns: None, str