code: def _get_device_or_current(
      device: tp.Optional[types.CudaDeviceSpec],
  ) -> Device:
      # Returns cuda.Device.
      # - If cuda.Device instance, it's returned intact.
      # - If None, the current device is returned.
      # - If non-negative integer, cuda.Device is returned.
      # - Otherwise: error.
      if device is None:
          return cuda.Device()
      if isinstance(device, Device):
          return device
      if not (isinstance(device, _integer_types) and device >= 0):
          raise ValueError(
              "Invalid CUDA device specifier: {}".format(device)
          )
      return cuda.Device(int(device))
  
imports: import binascii
  import functools
  import itertools
  import os
  import threading
  import time
  import typing
  import warnings
  import numpy
  import six
  import chainer
  from chainer import _backend
  from chainer.backends import _cpu
  from chainer.backends import intel64
  from chainer.configuration import config
  from chainer import types
  import chainerx
label_desc: Use image node_id 6 for calling a global function with example usage: _get_device_or_current(device) and returns: cuda, cuda, device