code: def setUp(self):
      super().setUp()
      accelerator_util.initialize_accelerator_system("TPU")
  
imports: from tensorflow.dtensor.python import accelerator_util
  from tensorflow.dtensor.python import layout
  from tensorflow.dtensor.python import numpy_util
  from tensorflow.dtensor.python import tpu_util
  from tensorflow.dtensor.python.tests import test_util
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 1 for calling the DeviceAssignmentTest obj's underlying member method code with example usage: obj.setUp() without return types