code: def test_init(self, backend_config):
      name = backend_config.chainerx_device
      chx_device = chainerx.get_device(name)
  
      device = backend.ChainerxDevice(chx_device)
      self.check_device(device, backend_config)
      assert device.device is chx_device
  
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 2 for calling the TestChainerxDevice obj's underlying member method code with example usage: obj.test_init(backend_config) without return types