code: def testCopyToGPU(self):
      if not test_util.is_gpu_available():
          self.skipTest("No GPU available")
  
      with ops.device("/cpu:0"):
          optional_with_value = optional_ops.Optional.from_value(
              (
                  constant_op.constant(37.0),
                  constant_op.constant("Foo"),
                  constant_op.constant(42),
              )
          )
          optional_none = optional_ops.Optional.empty(
              tensor_spec.TensorSpec([], dtypes.float32)
          )
  
      with ops.device("/gpu:0"):
          gpu_optional_with_value = optional_ops._OptionalImpl(
              array_ops.identity(optional_with_value._variant_tensor),
              optional_with_value.element_spec,
          )
          gpu_optional_none = optional_ops._OptionalImpl(
              array_ops.identity(optional_none._variant_tensor),
              optional_none.element_spec,
          )
  
          gpu_optional_with_value_has_value = (
              gpu_optional_with_value.has_value()
          )
          gpu_optional_with_value_values = (
              gpu_optional_with_value.get_value()
          )
  
          gpu_optional_none_has_value = gpu_optional_none.has_value()
  
      self.assertTrue(self.evaluate(gpu_optional_with_value_has_value))
      self.assertEqual(
          (37.0, b"Foo", 42),
          self.evaluate(gpu_optional_with_value_values),
      )
      self.assertFalse(self.evaluate(gpu_optional_none_has_value))
  
imports: import functools
  from absl.testing import parameterized
  import numpy
  from tensorflow.python.data.kernel_tests import test_base
  from tensorflow.python.data.ops import dataset_ops
  from tensorflow.python.data.ops import iterator_ops
  from tensorflow.python.data.ops import optional_ops
  from tensorflow.python.data.util import structure
  from tensorflow.python.eager import context
  from tensorflow.python.eager import def_function
  from tensorflow.python.framework import combinations
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import errors
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import sparse_tensor
  from tensorflow.python.framework import tensor_shape
  from tensorflow.python.framework import tensor_spec
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import test
label_desc: Use image node_id 9 for calling the OptionalTest obj's underlying member method code with example usage: obj.testCopyToGPU() without return types