code: def _create_tpu(gcp_credentials=None):
      return discovery.build(
          "tpu",
          TPU_VERSION,
          credentials=gcp_credentials,
          cache_discovery=False,
          discoveryServiceUrl="https://tpu.googleapis.com/$discovery/rest",
      )
  
imports: import copy
  import json
  import logging
  import os
  import re
  import time
  from functools import partial, reduce
  from cryptography.hazmat.backends import default_backend
  from cryptography.hazmat.primitives import serialization
  from cryptography.hazmat.primitives.asymmetric import rsa
  from google.oauth2 import service_account
  from google.oauth2.credentials import Credentials
  from googleapiclient import discovery, errors
  from ray._private.accelerators import TPUAcceleratorManager, tpu
  from ray.autoscaler._private.gcp.node import MAX_POLLS, POLL_INTERVAL, GCPNodeType
  from ray.autoscaler._private.util import check_legacy_fields
label_desc: Use image node_id 16 for calling a global function with example usage: _create_tpu(gcp_credentials) and returns: discovery