code: def test_from_array(self):
      arr = numpy.ndarray((2,), numpy.float32)
      expected_device = backend.CpuDevice()
  
      device = backend.CpuDevice.from_array(arr)
      self.check_device(device)
      assert device == expected_device
  
      device = backend.get_device_from_array(arr)
      self.check_device(device)
      assert device == expected_device
  
imports: import unittest
  import numpy
  from chainer import backend
  from chainer import testing
label_desc: Use image node_id 3 for calling the TestCpuDeviceFromArray obj's underlying member method code with example usage: obj.test_from_array() without return types