code: def testFromNone(self):
      value_structure = tensor_spec.TensorSpec([], dtypes.float32)
      opt = optional_ops.Optional.empty(value_structure)
      self.assertTrue(
          opt.element_spec.is_compatible_with(value_structure)
      )
      self.assertFalse(
          opt.element_spec.is_compatible_with(
              tensor_spec.TensorSpec([1], dtypes.float32)
          )
      )
      self.assertFalse(
          opt.element_spec.is_compatible_with(
              tensor_spec.TensorSpec([], dtypes.int32)
          )
      )
      self.assertFalse(self.evaluate(opt.has_value()))
      with self.assertRaises(errors.InvalidArgumentError):
          self.evaluate(opt.get_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 4 for calling the OptionalTest obj's underlying member method code with example usage: obj.testFromNone() without return types