code: def list_devices(device_type=None):
      """Return all the available devices based on the device type.
  
      Note: in a distributed setting, global devices are returned.
  
      Args:
          device_type: string, one of `"cpu"`, `"gpu"` or `"tpu"`.
              Defaults to `"gpu"` or `"tpu"` if available when
              `device_type` is not provided. Otherwise
              will return the `"cpu"` devices.
  
      Return:
          List of devices that are available for distribute computation.
      """
      return distribution_lib.list_devices(device_type)
  
imports: import collections
  import contextlib
  import os
  import re
  import warnings
  import numpy
  from keras.api_export import keras_export
  from keras.backend import KerasTensor
  from keras.backend import distribution_lib
  from keras.backend.common import global_state
label_desc: Use image node_id 1 for calling a global function with example usage: list_devices(device_type) and returns: distribution_lib