code: def get_tpu_drivers(
      tpu_api: discovery.Resource, project_id: str, zone: str
  ) -> Optional[List[str]]:
      """gets supported tpu drivers for given project, zone
  
      Args:
      tpu_api: discovery tpu api resource
      project_id: project id
      zone: zone identifier
  
      Returns:
      list of supported drivers on success, None otherwise
      """
  
      location = "projects/{}/locations/{}".format(project_id, zone)
  
      rsp = (
          tpu_api.projects()
          .locations()
          .tensorflowVersions()
          .list(parent=location)
          .execute()
      )
  
      if rsp is None:
          logging.error("error getting tpu drivers")
          return None
  
      return [d["version"] for d in rsp["tensorflowVersions"]]
  
imports: from __future__ import absolute_import
  import argparse
  import json
  import logging
  import os
  import pprint
  import re
  from time import sleep
  from typing import Any, Dict, List, Optional
  from urllib.parse import urlencode, urlparse
  import google
  import yaml
  from google.auth._cloud_sdk import get_application_default_credentials_path
  from google.auth._default import _AUTHORIZED_USER_TYPE, _SERVICE_ACCOUNT_TYPE, load_credentials_from_file
  from google.cloud.container_v1 import ClusterManagerClient
  from google.cloud.container_v1.types import Cluster
  from google.oauth2 import service_account
  from googleapiclient import discovery
  from kubernetes.client import V1Job
  from kubernetes.client.api_client import ApiClient
  from yaspin import yaspin
  from yaspin.spinners import Spinners
  import caliban.platform.gke.constants
  from caliban.platform.cloud.types import GPU, TPU, GPUSpec, TPUSpec
  from caliban.platform.gke.types import CredentialsData, NodeImage, OpStatus
label_desc: Use image node_id 5 for calling a global function with example usage: get_tpu_drivers(tpu_api, project_id, zone) and returns: unknown, None