code: def check_device(self, device, backend_config):
      assert isinstance(device, backend.ChainerxDevice)
      assert device.xp is chainerx
      assert device.supported_array_types == (chainerx.ndarray,)
      assert device.name == backend_config.chainerx_device
      assert str(device) == backend_config.chainerx_device
      assert isinstance(hash(device), int)  # hashable
  
      # fallback_device
      chainerx_device_comps = backend_config.chainerx_device.split(":")
      if chainerx_device_comps[0] == "native":
          assert isinstance(device.fallback_device, backend.CpuDevice)
      elif chainerx_device_comps[0] == "cuda":
          assert isinstance(device.fallback_device, backend.GpuDevice)
          assert device.fallback_device.device.id == int(
              chainerx_device_comps[1]
          )
      else:
          # Currently no such ChainerX device is known in Chainer
          assert False
  
imports: import unittest
  import numpy
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import testing
  from chainer.testing import attr
  import chainerx
label_desc: Use image node_id 1 for calling the TestChainerxDevice obj's underlying member method code with example usage: obj.check_device(device, backend_config) without return types