code: def device_count(
      backend: str | xla_client.Client | None = None,
  ) -> int:
      """Returns the total number of devices.
  
      On most platforms, this is the same as :py:func:`jax.local_device_count`.
      However, on multi-process platforms where different devices are associated
      with different processes, this will return the total number of devices across
      all processes.
  
      Args:
        backend: This is an experimental feature and the API is likely to change.
          Optional, a string representing the xla backend: ``'cpu'``, ``'gpu'``, or
          ``'tpu'``.
  
      Returns:
        Number of devices.
  
      """
      return int(get_backend(backend).device_count())
  
imports: from __future__ import annotations
  from __future__ import annotations
  from collections.abc import Mapping
  import dataclasses
  from functools import lru_cache, partial
  import importlib
  import json
  import logging
  import os
  import pkgutil
  import platform
  import sys
  import threading
  from typing import Any, Callable, Union
  import warnings
  from jax._src import config
  from jax._src import distributed
  from jax._src import traceback_util
  from jax._src import util
  from jax._src import hardware_utils
  from jax._src.cloud_tpu_init import maybe_import_libtpu
  from jax._src.lib import cuda_versions
  from jax._src.lib import xla_client
  from jax._src.lib import xla_extension
  from jax._src.lib import xla_extension_version
label_desc: Use image node_id 25 for calling a global function with example usage: device_count(backend) and returns: int